Answer:
The meaning of this saying “I don't need a friend who changes when I change” means that you don't need a friend that copies your every move or tries to strictly be like you, or sometimes that "friend" that copies your every move and agrees with everything you say wants to win you over or just wants you to like them. You don't need a friend who doesn't know how to be themselves and try to be you because of that instead of trying to find themselves.
"I don't need a friend who changes when I change and who nods when I nod; my shadow does that much better."