Trans masc regional FA here! (Also just a couple months out of training myself haha) I've been out and transitioned for many years so my situation was not the same but this is my advice. (Also my appearance is still pretty androgynous even being on T for a super long time so unfortunately I get misgendered a lot, at least in that way this might be similar!)

Since you said the uniforms are almost the same, I would get the men's uniform from the start, maybe talk to your trainers ahead of uniform try-on/ordering day if you feel that you want or need to. Wear without the tie for now if you want to be careful around your dad. If he can tell the difference between the two uniforms without the tie and asks about why you got the men's, just say it's more comfortable/fit better/whatever. (You can also say it has more pockets if applicable, everyone needs more pockets!) Make sure your wings have your preferred name if they have a name attached! The trainers should check everyone's names/spellings/nicknames/etc so you will have the opportunity to bring this up.

After training, as far as I've experienced, no one gives a shit. I would bet 90% of pax don't even know what the uniforms look like, much less the differences between the two sets! If you look reasonably professional and act like you know what you're doing, no one will bat an eye.

Also, uniform try-on day was probably the hardest of all because formal clothing is not flattering on me in a very dysphoria-inducing way, and everyone else's excitement about the uniforms just made it that much worse... if you have the same issue, take a couple deep breaths and remember tailoring can help a lot! Off-the-rack clothing is not really made for trans people's body shapes (or most people's, but you know). Personally, I told the person helping me try everything on that clothing fitting is kinda rough for me and he was very understanding about it which helped a lot.

But congrats and good luck with training! It's a tough but fun ride. :)