Welcome!
If it's OK to give a bit of response in this thread:
If you're certain that you want to join the military, then do not get any surgeries done. I think breast reductions would be fine but can't guarantee it; hystos are serious enough that you'd probably have to apply for a waiver.
Once you're in the military, it will be more difficult for you to get the treatment you want, but somewhat less likely that it will prevent you having a career if you do manage to get it. Once they've invested the time and money in training you they're reluctant to let you go. Unless, that is, you're gay.
Which brings me to another point: if you like women, you're gay as far as the military is concerned. Which means you either have to be celibate or live a double life at least until DADT is fully repealed. And there's still no guarantee that it will be repealed, or if it is, that it will come with a non-discrimination policy.
And another point to consider is that if you have any
gender dysphoria in addition to your physical sex dysphoria, it could be worsened by the fact that so many aspects of military life are controlled by your gender. If you have problems being socially sorted into the "females" category, you may have problems in the military. I did. You may not necessarily be sure how you'll feel until you try it.
Luckily, though, you don't have to commit to a 20-year career right away - you can start with 4 or 5 and see how things go