Remember, as was posted for you in another thread, the nomination applications run concurrently with the West Point app at this point in time. Start working on the nomination NOW.
How, you ask? Sign into college board and pay to have your existing scores sent to the SAT/ACT codes for your two senators and your house rep. Get your counselor to send transcripts to each. And, most importantly, because time is a factor, figure out who you want to write your recommendation letters and contact them and get the working on it. On that same note your Senator/house rep may have a recommendation FORM that needs to be completed in lieu of/conjunction with the LOR's. Check the website.
You really need to go to the websites for each of your MOC's. many of your questions will be answered by their instructions.
ETA - this can be a little confusing, but USNA and West Point do not require Letters of Recommendation. Rather, when the second step opens up, you will enter the name and email address of 2/3 teachers (English and math, plus science for WP. They will then send in their School Official Evaluation directly to the service academy. LOR's for noms can be from coaches, scout leaders, etc. It's best to give them the name and address of each MOC so they can crank out the same letter to all three and you don't have to go back to the well several times. And don't forget to provide them with the Recommendation Form if required.