There are two blue and gold tents. One is as Hoops describes, on the Gold side of the stadium. The one on the Blue side, nearest the Blue Angel jet, is the Supe's tailgate venue, invitation only, for official guests. You'll know if you're at the wrong one, because suited and sunglassed people with earpieces are often seen there.
There are also plenty of the usual food vendors in the stadium, along with booths at concourse level offering pulled pork, chicken tender platters, fresh grilled burgers, etc. That's a perfectly fine way to go, especially if you've had a nice lunch in Annapolis. Typical stadium prices. Find a place to perch and enjoy.
The USNA Alumni Assn also has a ticketed tailgater in a tent, open to parents. Catered with seating. Registration for these closes some X hours before game day.
http://www.usna.com/page.aspx?pid=509
The Akerson Tower is run by the Athletic Assn (NAAA), still a fairly new deal, for a certain level of donors who are then able to purchase club seats on top of that. At least that's the way I read it, no guarantees I have got it right. I've been there to functions but not football game day.
http://m.navysports.com/m/tickets/navy-tickets-m-footbl.html
What you don't want to do is be caught in the stadium security line outside as parking lot tailgaters surge to the stadium entrances to get to their seats for March On and flyover. If you want the right-over-your-head experience for the flyover from first sighting in the distance, stand on the open concourse near the refreshment stand at the Navy end zone. That's the water tower end of the stadium. Flyover can be seen from all seats. Then mosey to your seats if you like.
Another fun option is the famed New Jersey Parents Club tailgate. They have a massive tailgate and feed any mid who wanders up.
http://www.usna-njpc.org/site/mobile?url=http://www.usna-njpc.org/Tailgating_Essentials.html#2741
Your mid is in a duty status until after Blue and Gold is sung at game end. Depending on how strictly they are enforcing the rules, plebes/mids don't get to wander around much during the game. They are supposed to be in the Brigade seating area or in the Blue concourse for chow and bathrooms, so chilling at the Captain's BBQ is not for them. If they choose to meet up with you, you can swap texts in advance, get their favorite food and meet them in the Blue Concourse when they pop out for food. The lines get large at the half.
Hats. Sunscreen. Enjoy!