Shalom! Can you take challah for hafrashas challah, shape it, and then bake it the next day? Thank you!

Yes, but if you are asking about the challah which you "took off", there's no need to shape it or bake it, just burn it, or at least wrap in 2 bags/foil before disposing. And if you are asking about the challah which you wish to eat, you can shape it and/or bake it whenever you want. But if you plan on freezing the dough, and then baking small amounts of it on different occasions, many hold that you can't make a bracha on the initial hafrasha in this case, if there isn't the minimum amount for hafrasha with a bracha in at least one of those bakings.