Most Helpful Guy
I don't think that there is a set age to move in with somebody. Sure it's a little young, but age is not what I'd base my decision on. What I think is that you should more consider things like whether or not you both can afford it, whether you have the money or any good plans for if things aren't going financially well.
As for when you move in with your S.O. I think it's probably a good idea to have been dating them for a couple years before you get into that. Even then, you should have a good hard think about how your relationship is going. Is there a lot of fighting? Hows trust going? Any jealousy issues? Any other problems you have right now? I think things should be worked out before two people move in together. Seriously analyze whether you think your relationship is stable. Even then, do you think you will be able to handle it if things went south? Make plans. Have exit strategies for just in case.
I will say that it IS a learning experience, but it's something you should prepare for. You don't want to dive at it without thinking hard on it, first.