I want to go part time college but I'll be active army?

I'm currently a senior in high school and I've decided to join the Army. Of course it wasn't easy. My father has almost completely shut me out of his life bc of it. I was always told I would be successful bc I would be a doctor or go into medicine. Well I didn't really agree with that bc I've always loved working with my hands and building. My job in the Army is to be a 12W Carpentry and Masonry Specialist. I've always done very well in school. I want to be able to get some school in while serving for the next 4 years. How should I do this? Online? Idk how else I would do it since I'll be on missions and stuff. I need some help. What kind of major should I look for? Engineering of what type? I just need some ideas maybe based on experience. I'm really happy I've decided to serve my country but I also want to start a very successful career when I am done serving. Thanks!