(If i’m not wrong, green-ish user here) When you click on “Communities” that’d be only the communities inside the instance that you made your account in.

I generally use this to look for specific communities: https://browse.feddit.de/ It should look across all lemmy instances to find the one you wanted

Managed to make me post and comment at all, which is more than reddit has ever done to me. Literally made my account around an hour ago too.