AFAIR, Bandcamp doesn’t tag their files at all.
So you’d need to insert the basic tags yourself.
Here is how tags are supposed to look like: Need help sorting albums with same name - #2 by OttoKerner
Combine this with a folder structure like this: https://support.plex.tv/articles/200265296-adding-music-media-from-folders/
With rather obscure artists, it is probably best to enable “prefer local meta tags” in the library’s properties.