I have some questions, and I don't know how to start

Hey, I'm not sure if this is the right thread... But I Googled these questions and nothing came up: I keep getting a notification saying I need to have an account to join group chats, but I am currently logged in on my account. What's going on?

Furthermore, I can't figure out how to get to my account profile to change my picture (I've gotten an alert saying I can now.)

Help??

Thanks