BuddyPress.org

So I have a bit of a dilemma. There are two types of users on my site. However, the default one comes up immediately. I don’t see where people can choose.

Ideally I want the two types to choose what type they want to be, and then that can’t be changed unless done by an admin.

Is this possible at all? Should I have one default group and then they can choose to form other groups?

Let me know if you need more information. it may seem vague without being very specific.

Thanks!