I've learned enough here by reading that I could fill hundreds of pages with information. I prefer reading information to looking at photos. I learn techniques, how to solve problems, and what gear I absolutely must buy. I always look at the Gallery, but information is my main interest.

Yes, posting a picture as an example - good or bad - is a good idea.

As many people have complained, they post a picture or two, but it soon disappears in the long queue of pictures posted by the other 86,000 people on the forum.

There is little difference between the crop sensor DSLR and a mirrorless DSLR in size or weight. I have both and they work in exactly the same way 90% of the time. occaisionally I use the 'zoom in' focus option that is offered with the electronic viewfinder on the mirrorless. The live view's ability to show different exposures prior to shooting is also a plus. It is lousey on my old canon even tethered.(age)

Macro and lighting is always a problem....its not the camera it is 'the proximity' of the subject. Unlike a cell phone or point and shoot, the flash and ability to capture in low light in a dslr is much less. because you are capturing a larger and more detailed image than in a cell phone. To get around this you need extra passive light or a circular flash attatchment. Macro, as a subject, you need to read up on in much the same way as you would for 'portraiture' or 'landscape'..each has its 'tricks' and skill sets as well as 'kit to buy'.
Look at sites like DPreview. It will give you all the answeres you need on the +/- of every camera you can think of.

have fun

Pictures look great. Market worthy, maybe, but though very good, are amongst millions of pictures with he same quality, and similar scenes. You have to get some very unique pictures, or present them in a way that is entirely unique. Plus name recognition is critical. A photographer taking pictures from a large studio in New York can have a bigger name recognition thus sales potential than someone like me, a no name. I can take the same Ansel Adams photo, almost exactly, make a blow up of it, put it in a nice frame, and it won't sell. Put Ansel's name on it and it may be worth many $thousand. My thought anyway. I happen to know a guy who sells some pretty nice sunset pictures on the boardwalk. I rarely see anyone looking at them.

There's a 35-70 "kit" lens available for those oldies- they kinda suck,
The newer Nikon "G" lenses don't have external aperture for you- they will suck.
Tho many "D" lenses will work fine. Google their specs to make sure all adjustments work in manual.
Walmart and Costco will develop your film fast and cheap. And they're pretty good.
Most Carap-to-Nikon adapters don't really work. And if they do you lose a few stops. Meaning you better be shooting outside in bright daylight. Or it will suck.
Youtube has quite a few videos on the matter. Only some suck.
I *just* got rid of my last "F" camera, tho I still have a pair of EMs. They don't suck, either.
Just like the electric ones: Know your camera first. Take your time. Hold still and shoot.
I still think film makes prettier pictures.

Two BIG thumbs down!
Some shooters don't have unlimited income. Do I pay the mortgage or buy the lens?
Some shooters either choose to or have to stick to a budget. We can't go visit the kids this year, because I bought.....
Some shooters will only be posting to social media where the difference in image quality is negligible.
Some shooters will only be printing 4 X 6 for their personal albums.

In brief there are those who don't share priorities but don't merit being called cheap bastards.