Tips for moving across the country?

My mom is from Alabama, she bounced around southern states but always went back there. We landed in Montana because of the military and all I've ever known is Montana. Sure, I've gone to Alabama in the summers to visit family but never longer than a month. So it's gonna be a huge change. Not only that but I'm also going into a smaller private school for the first time, with uniforms. So I'm going to be the "new girl".

She brought it up a few days ago, to move back down there since she's out of the military and we have the funds to do so. She viewed it as good to have more experiences and that it might help with my PTSD symptoms. So we made the final decision to move across the country this summer and renovate our new house and then start up school come fall. I was already going to move to Alabama to go to college, I wanna go to ASU so it's just cutting the time before I move down two years.

Now I'm excited. I really am. I'll be with family, I get to start over and the new house we're moving into is really nice and I get to pick my room. I don't have any super close IRL friends, except one..  And that's kinda my problem there. I'll really miss them. I'll really miss our hang outs and laughing with them at lunch and going to the movie theatre. They're amazing. I'll miss my art club and my old teachers and my drama troupe. I'm going to leave everything I've known behind. 

There's a small comfort in the fact I'll come up most summers, and a hope that'll I'll see my friend again and hang out. I'm just nervous and a little nostalgic for everything I'm putting behind me. I was wondering if anyone had any tips? For private school or moving in general. Would be greatly appreciated.