I made a mistake in my PC I change folders and renamed.

I made a mistake and moved files and renamed them on my PC. LRc now can't find the file. Can I delete the catalog in LRc and import the new, renamed files?

By @juliannah79809637

Yes you can do it, BUT if you do a reimport you will lost all editigs that you've done to this images. I wouldn't do it!!! 

This article should be help: Lightroom thinks my photos are missing—how do I fix it? | The Lightroom Queen

You can also try to rename the files to the original name with which it imported to Lightroom and move it to the original location. 

That can be a big mistake to make if you did the moving and renaming to many folders/files outside of Lr-Classic.

If you have a backup of the folders and files with their 'old' names, and in the same heirarchy  as Lr-Classic knows- you could replace the (moved, renamed) folders and files with those from the backup and so Lr-Classic will see them as before. 

If you moved/renamed only a few folders/files- renaming and moving them back to their old names and locations where Lr-Classic thinks they should be is suggested.

The 'New Catalog' route is easy but you will have lost any and all work (All editing, Collections, keywords, etc, etc) which would be very disappointing.

(A new catalog can be created from the [File] menu, if you want to go this way.)