Advice needed for Girlfriend of BUDS Seal Candidate

Hi everyone! My boyfriend left for BUDS almost two weeks ago and I’m missing him a lot. I am so incredibly proud of him for doing this, and can’t even begin to describe how much I admire his strength in his faith to push him to do this. I want to support him as much as I can because I know how important this is to him, however I have zero clue about how military life works. (I’ve never dated someone in the military, nor had family in it) We are trying to do distance so being able to see him will have to be planned, but I’m hoping to get out there as he progresses. We are in our late 20s so thinking about marriage etc. Any tips on how to support him? What should I do to stay grounded when he’s busy and can’t talk? Should I tell him I miss him or will that mess up his mental game while he’s there? I work as a full time accountant and have a fairly busy life running marathons, taking care of my health, playing soccer in intramural leagues etc. (both playing college sports and that is sort of what brought us together haha) . I’ve been trying to do a full crash course on how to do things right,(we are talking many YouTube videos of Military Life) but could use some more help :) Thanks everyone <3 S.M.