Congratulations, you have successfully made beautiful Frozen garlands! All you have to do is hang them wherever you want!
Practical tip 1: if you don't want to hang them with thumbtacks to avoid marks on the wall, use decorative patafix (it supports up to 2 kg and is found in supermarkets)! And you can hang it wherever you want like that!
Practical tip 2: keep the garland after the birthday and use it as a room decoration!