Ron 717 Loc: Pennsylvania

Search your area for a camera shop, yes there are still some around, go there and hold the inferential brands and models. Ask the shop employee questions, get his recommendations and go from there. The prices at a camera shop are usually the same as online because the camera manufacturers set the prices. The camera shop operator will answer all of your questions, he wants you to come back with additional purchases.

joer Loc: Colorado/Illinois

As a complete neophyte, your budget is way too high for a starter camera Check out some used equipment from KEH or MPB for about $1000 or less and use it until you have an idea of what is it you like to shoot and what level of complexity you can handle.

Strangers can not possibly choose correctly for you. There are plenty of YouTube videos available to provide information on equipment and how to use it. However be aware that all are salesmen interested in promoting their own agendas.

Check out Steve Perry...he understands his craft and usually gives sound advice.

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

Sony 200-600 mm zoom, about 2K. And a Sony a9, excellent condition, about 3K. You will love it.
I would also recommend the Canon R5 and Canon 100-500, it may be slightly over your budget.

BebuLamar

I think you should take up another hobby first. Studying the cameras.

anotherview Loc: California

You will receive a boatload of advice and suggestions for your post.

Let me add mine: Once you settle on a camera and lens, rent to try before you buy.

I can highly recommend that you also attend one or more workshops in both camera operation and photo-editing, to speed your learning and to produce a foundation.

Study and apply image composition as the prime exercise after camera operation. Effective composition will produce worthy photographs sooner.

As a craft, photography requires much practice. Learn from your mistakes and successes.

PS: If you own a newer cellular telephone with a built-in camera, you can use this camera to learn photography. You do not need to spend your $5000 on other gear. Besides, after you become familiar with photography, your experience with your phone camera will guide you when buying a standalone camera.

Good luck.

Jimmy T Loc: Virginia

Just Starting Out In Photography
I strongly recommend starting with:
1. The exposure triangle - https://www.youtube.com/watch?v=3eVjUrY9a9c&t=5s
2. Then move to your camera's controls and learn what they do and how they control exposure.
3. Follow by reading Bryan Peterson's book Understanding Exposure, $15.99 - https://smile.amazon.com/Understanding-Exposure-Fourth-Photographs-Camera-ebook/dp/B0104EOJSK/ref=sr_1_1?crid=BCE9Z9HNNCJ7&keywords=bryan+peterson+understanding+exposure&qid=1585223021&sprefix=bryan+peterson%2Caps%2C137&sr=8-1
4. Use these free Bryan Peterson videos. They are very short, usually 2-10 minutes long, easy to understand, and will simplify your photographic education.: https://www.youtube.com/watch?v=k9z4zfVVan8&list=PLC807CCF3F5186201&index=1
5. When you are learning, remember that the "P", and "A" camera modes are your friends.
Shoot a scene in "P" or "A" mode, then take a shot of the same scene using settings you select and compare the results (note differences) of (Exposure Triangle) shutter speed (SS), F-Stop, ISO, etc.
Above all, remember that photography is fun, and rewarding, so enjoy your photographic journey and don't forget to . . .
Smile,
JimmyT Sends

Edit: Looks like you already have plenty of advice on how to $pend your $$$, grin.
I would spend a bunch of time doing the recommended reading and watching the videos BEFORE spending the buck$.
Edit II: Another great learning tool: https://www.youtube.com/watch?v=iWfdxE1om6A

gvarner Loc: Central Oregon Coast

It would be helpful to know your current level of knowledge about photography. Also, are you computer literate? I view digital cameras as a computer accessory, not just a picture taking device.

imagemeister Loc: mid east Florida

Sony A6600 and/or Sony RX10 IV. Lenses for the A6600 can vary widely and will need close investigation by you.
.

imagemeister Loc: mid east Florida

Yes, sadly, MANY have this view ....

monroephoto

Out of all the vast sources of information available today, some free, some at a price, I have received the most benefit from a group called Kelby One. It is run by the number one best-selling author on digital,photography, Scott Kelby. Annual membership runs between $149to $199 but I believe you can get a FREE thirty day trial subscription. Check out a number of the video classes offered on gear, nature photography, and any other subject that may interest you. This site presents many classes, taught by leading photographers and post production experts. (Lightroom, Photoshop, etc.) (I guarantee you will want to learn how to edit what you've shot!). Best of all, this easily allows you to take it step by step, without feeling overwhelmed. I began with a fairly simple camera with a kit-lens and now have multiple flagship cameras, more complex, used to shoot college sports. I wish you the very best of luck on your decision-making process and hope you find yourself amazed at how much you've learned and enjoyed in the next year.

2buckskin Loc: Wyoming

I also retired and although I have several hobbies, decided to take my photography more seriously.
I researched online and decided to purchase a FF canon 6D with a low shutter count which saved several hundred dollars. The brand makes no difference the way I see it just get familiar with the features of the camera you purchase.
I also purchased used Canon L series lens from local sources and from KEH, this way I wasn't purchasing cheap lens that I would later upgrade to better glass. I already had the computer covered, and did a lot of online tutorials on editing the images in Lightroom, and I am slowly learning Photoshop.
Most of all just enjoy your retirement and the new hobby.

DirtFarmer Loc: Escaped from the NYC area, back to MA

$5K is a pretty good budget for a camera, but as a newcomer I would not spend it all at once. Start easy and learn, and you will eventually find you need something you didn't start with.

Photography is more than equipment, so get yourself a mid-level camera (or even entry-level) and take photos. You can explore the other aspects of photography and find out where your interests lie. Eventually, $5K will start to look small. But I'd guess $1-2K is probably good to start with.

As far as gear goes, the lens is what makes the image. The camera just records it. So reserve a good part of your budget for lenses.

n4jee Loc: New Bern, NC

Put $4500 of your budget in escrow for at least a year. Buy a Panasonic Lumix DC-ZS70 Digital Camera. It has a Zeiss Lens with the equilivent range of 24-720mm on a 35mm camera. It has a 20mp sensor which will allow decent sized prints. It has a viewfinder so you don't have to try using the rear screen in bright sunlight. It will fit in your pocket so you can have it with you at all times. It has all the controls you need to learn photography. It can be had for $350 or less most anywhere. You will still use it after you upgrade and buy your dream camera.
I have bought them for my wife and my daughter. I myself have a later model of this camera that has a larger sensor and less zoom range. I have both Nikon and Sony gear and my Panasonic gets the most use.

jim in TC Loc: Traverse City, Michigan

As a long-time but purely amateur photographer I was leaning in the direction of this advice. There are other worthy cameras in this category and you will have a far more nuanced appreciation of the direction you need to go when you spend the bigger bucks. As you have seen there is a lot to learn, and much of that 'book-learning' is of great value as you learn the basics and beyond. Good luck!

olemikey Loc: 6 mile creek, Spacecoast Florida

As you nail down photography type/camera type/etc., also consider the purchase of (or go to library/on-line videos/youtube/etc.) of a good book or two on photography to educate yourself. Yes you can start out with a camera set to "Auto" and it will generally do everything for you, but if you want to learn the who/what/where/when/why of it all, you can save yourself a huge amount of trial and error time. You might/might not grumble about some "schoolin" now, but you will be thankful later, and you will know and understand what is happening as you "do work". The same thing goes for the "Post Processing" of your images. Some folks are happy with "Straight out of the camera", but there is another whole wonderful world with the computer aided programs that replaced the darkroom.

The idea of checking with a local club, renting prime candidate cameras, will all help you. A DSLR is a good starting point, but mirrorless is the future, so you would probably want to concentrate on that (many of us have and use both)... New is great, secondhand is great, refurbished is great, just use due diligence in your approach and you will make good decisions (And we are all here for you, we've all "been there", whether it was last year, last decade, or many decades ago!!!

You can get great results with almost any type camera if you know what you are doing - however, if I had a $5K budget, a good prosumer mirrorless (I'd want a viewfinder on whatever I bought), and a couple of quality fast lenses covering wide to at least medium telephoto (or a longer telephoto if wild birds are in the plan), and a minimal amount of extras (tripod/monopod/bags/lighting/fast cards) will help.....Anyway, good luck, good hunting, and welcome to the forum!!