Leanne, I would just write a short page, saying Hi, how are you, how are you settling in over there? He won't be able to tell you too much about what's going on his daily life (people in the Army tend not to) so be prepared for that - but you can tell him about what you've been up to. End it saying you hope that he'll write back soon. I wouldn't give out personal info or get into deep discussion about anything - you haven't know him long enough. Just write and say hi, and leave it to him to write back. If he doesn't reply in a couple of weeks, you can send a follow-up saying, did you get my first letter, I'm not sure how the postal service to the Army overseas works? - and so on. Keep it light!