i have a boyfriend who is okay most of the time but is moody like a girl and doesn't tell me where he is and me and his best friend are enemies and he chooses her over me so i'm just waiting until after prom to free myself of him :(

Just because you’re moody doesn’t mean that you are a girl. Or that you should be compared to a girl. Being moody is being moody and being moody is what humans do, not just women. Him being moody should show you that he is at least able to feel, which is a good thing in his case. You need to understand that first before you try to understand everything.
If you trust him, he shouldn’t have to tell you where he is all of the time. You should know that he is not doing anything wrong, or to deceive you, and if you think that he is, you should rethink about your relationship with him because what’s the point of being with someone if you cannot even trust them going to the supermarket.
It’s hard to pick sides between your partner and your best friend. Mostly if your partner is paranoid over things that aren’t there, or who questions them at all times. A best friend trusts their best friend, and that’s why they call them a best friend, so it’s probably easier for him to speak with her when she is not angry with him / upset with him / making him feel as if he is doing something wrong. If you love him, you would try to make mends with his best friend, or explain to him why you don’t want her in his life.
If you are breaking up with him after prom, why does any of this sort of stuff even matter to you, and why are you even thinking it over?
Do people still go to prom? Because I thought that stopped being a thing after Sixteen Candles was released.