I need some advice?

So, I'm currently seeking a relationship with this girl that I've been friends with for years. She's honestly one of the most amazing, beautiful, and wonderful person I've ever met (she has such a beautiful smile, oh my gosh!!) I'm only 15, and I've already begun imagining a future with her in my life. And I've trying to get the courage to ask her to be my girlfriend (that's a post for another day! 😉 )

There's one tiny problem though...

She wants to go into the military when she turns 18 (she's turning 17 soon). I'm more than happy for her and I fully support her because this will make her happy. But that means that if I do get into a relationship with her (I'm hoping!!), it would have to be long distance. Do you guys have any tips on how to make LDR work? (And also maybe a little advice on how to ask her out?)

This is so stressful, because I want to spend as much time with her as I can, but I can't really do that until we make that first step together. I really do think I love her, she's perfect, and it would be more than the best if we could spend our lives together.