Need Guidance on Best way to Move to a new PC

Specifically, when I tried to import a large number of photos at once, it errors out.

Please give us the details. How many is a "large number" of photos? Describe in detail exactly what happens. What is the exact error message, word-for-word, unedited?

The problem I have now is that I tried starting fresh to see if it was related to the size of my catalog.

The only time size of catalog matters is when you make backups, larger catalogs take longer to back up. Your problem is unrelated to size of catalog.

The problem I have now is that I tried starting fresh to see if it was related to the size of my catalog. I didn't realize at the time that in addition to losing my keyword tagging, I would also lose my edits.

This is not true. If you do it properly you lose nothing. I have done this several times. See the link from @DClark064 for instructions. Re-importing the photos is not a step in the process, and in fact is the wrong thing to do.

I agree with the others, the first step is to try to solve the existing import problem, and you need to show us your System Information from the LrC Help Menu, as well as providing the information I asked for above.

Although I use Macs, I agree with CMass that it should be reasonable to expect a recent Windows 11 PC to run Lightroom Classic well, and maybe it would be better to troubleshoot that first. Especially trying the command File > Optimize Catalog. 

Also…

The problem I have now is that I tried starting fresh to see if it was related to the size of my catalog.

By @WarEagle96

…it shouldn’t be directly related to the size of the catalog. You do have a lot of images but larger catalogs have been mentioned as working fine.

Yes, image edits are stored in the catalog where that image was edited. That means two different catalogs referencing the same images could store different edits for the same referenced image. This is also why starting a new catalog won’t show any edits made to the same image in any other catalog.

But, if you started fresh and wanted to bring over the edits from the other catalog so you don’t lose them, you could start with an empty new catalog and then use the command File > Import From Another Catalog. That brings over just about everything: Image database entries with their edits, annotation metadata (captions, keywords…), membership in collections, and more. 

I say “just about everything” and not “everything” because I’m not sure Import From Another Catalog preserves every last bit of metadata like membership in Publish Collections and what profiles are loaded for soft-proofing and printing. But Import From Another Catalog is a lot better than re-importing images into the new catalog, which is basically starting over from nothing.

https://www.lightroomqueen.com/how-move-lightroom-to-new-computer/