before you do anything related to whakama, you gotta invite him first. simply click THIS TEXT and you will be brought to the invite page where you can select a guild to add whakama to.
once you've added whakama to your guild, it should send a welcome message in the first channel it sees, usually being a channel that @everyone can chat in. from there, you can see all of the permissions that should be set up automatically but they are just there in case they weren't somehow.
however in some channels of the server permissions might be broken in some way since every permission can't be accounted for and every guild is different, so if not everything works i'd recommend reading the next part of the documentation in this section.
have fun with whakama!