How Roles play with levels

I was using s2members before I signed up for wpmudev now I'm using membership. However my users still have set roles that were alligned with s2members.

I've deleted that s2member plugin but the user roles are still showing. I'm not sure what role to reassign them to so that the membership plugin will control that.

At first I want someone to join and be a part of the community(buddypress) but they wouldn't see the wp admin panel.

Later we will add the ability to create their own site.

Does it matter if they are just left at the subscriber level? Or how would moving them to member affect their interaction?