Hello,
First of all, congrats on starting the application process. This is a great resource for all your service academy needs. If you have already submitted your Precandidate questionnaire, that is your first step. The bulk of the application will come out near the end of June (including the CFA). You have missed the deadline for Summer Seminar (Feb 28), but don't worry about that. Summer Seminar does not have an impact on your admission to the academy. If you are dedicated and willing to work hard, that is what counts. I am one of many appointees that did not attend Summer Seminar.
As for what to do now, there are a couple things you should be working on. First is the CFA, it won't open up until the end of June, but you should start working out yesterday. Don't expect to do well on it if you just show up without any preparation. Be prepared to max it, or at least the best that you think you can do, the first time you take it.
If you haven't gotten in contact with your ALO, now would probably be a good time to at least get the conversation. Remember, you are not starting late in the application process for the academy, you still have lots of time.
Also, start looking at the nomination packages provided by your members of congress (MOC), or request them if they aren't online. You will need to start working on the essays they request and will need to alert teachers, coaches, and other officials that you will need their recommendation. Start asking them now and and they might be ready by the time you need to submit your application.
I believe that I received the request from DODMERB this time last year. Get that out of the way as fast as possible because complications will usually pop up later on.
Good luck on your application, start getting things together now so that you will be able to get your application in early. Do your best, get it done, and have no regrets as you go through. If you have any other questions, feel free to ask.
Later,
Brian