I'm going to rent my condo out and move in with a friend. Should I form a LLC as a landlord?

That doesn't really make sense, unless you're going to put the title to the condo unit in the LLC's name;  before you do that, you need to find out how that would sit with the mortgage lender and with the condominium association, because you probably can't do it if either one objects.

I'm not sure why you'd want to do this, since the potential liability you'd be facing wouldn't be anything you couldn't insure against, at reasonable expense.