I find that most of my frogs are communal and like having a mate or two around. It's really up to your discretion, as they can be perfectly fine alone as well. Definitely be weary of size differences because they can eat one another. You'll probably need to find an adult if you want your frog to have a friend. Moreover, if you do find an adult...be sure to keep them separate for a bit just to make sure one isn't sick and then infects the other.