sandiegosteve Loc: San Diego, CA

I was going to say "pump the brakes" but it may be too late.

It might be worth getting out a pad of paper and writing down where you have your images. Lightroom CC Classic will point to images on your hard drive. The catalog just stores information about them including your edit history.

So, I like to create a new folder somewhere named "photography". I also put that on it's own hard drive. Then, I slowly move things into that folder and organize how I like it. For the most part, that is by year, but I also break out key events/jobs. Just add a little at a time to the catalog.

Then, you also have one point to backup which you should factor in.

Jaackil Loc: Massachusetts

You didn’t say which version of Lightroom you are using. But There are two easy fixes. First you could just create a new catalogue and start fresh. Or you can just go through your current catalogue and delete the images you do not want in there. Deleting from a catalogue does not delete them from your hard drive. Lightroom stores no images. It only catalogues them.
You may possibly be able to quickly find the images from your computer that you don’t want by going into library view. In the left panel click on folders and search for the folder that has the images you don’t want. If you are on a PC they might be in My Pictures or maybe you know the name of the folder they are in, it should be listed.
If you are going to go with the first option I would suggest setting up some system of organization whether it be by folder or date or what ever you decide(there are tons of video tutorials on how to organize Lightroom) It is always best to have a system in place from the beginning rather than try to re organize an existing catalogue if you are relatively new to Lightroom. Good luck.

clickety

This will not help you, but know that many off us can relate.

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

There is no need to create a new catalog and start fresh. Your catalog is just a file. You can copy it. Give it a new name (maybe include the date) and you have a whole new catalog with all the same photos (and edits) in it. The old catalog is still there. You can ignore it or back it up or whatever. But it's probably a good idea to keep it around while you adjust things to your liking.

Once you have a new catalog with everything in it, you can then start to think about what you don't want in the catalog. You can delete things one at a time or you can try to find a common characteristic of the things you don't want (e.g. none of the unwanted things have edits). Make a smart collection that selects those things. View the collection and select all the images. Then you can delete them. You will have to switch the view first because if you delete while you're looking at a collection, you only remove the things from the collection. If you select everything in the collection then view "all photos", the collected images are still selected and you can delete them all with the delete key. Select "remove from catalog" rather than "delete from disk".

If you make an error and delete something you didn't want to delete from the new catalog you have two choices. If you made a lot of errors, you can start over and take the old catalog and copy it again to a new catalog and start deleting things, or if it's only one or two items you can go to the old catalog, select the things you want back in the new catalog, and export them as a third catalog. You can then merge that third catalog with the new catalog. Edits preserved in this process.

GeneC123us Loc: Sugar Land, TX

In Catalog, you can filter on file type, in the Text Filter. For instance, icons are .ICO, so run the filter using *.ico and remove the resulting files from the catalog (don't delete). I don't know what other formats are used for buttons or other type graphics. Good luck.

crphoto8 Loc: Anaheim, California

Another way is to create a second catalog and import to it the images you want. Then you can either ignore your current catalog or delete it. Tell LR to open the new catalog when LR is launched and you're set.