Hey, I just want to serve my country before I’m to old too.
You're entering a game designed for an 18 year old at 30. There are ways to do that which won't make your life absolutely suck for the next few years. You won't be able to hang out with the other sailors your age because they'll all be well outside of your peer group, and that's fraternization. Your peers will largely be fresh out of high school, 10-12 years younger than you. Your immediate superiors are going to be 8ish years younger than you.
If you're single, your living situation is going to take a huge nosedive.
At 30 enlisting into the (Air or Army) Guard/Reserve side of the house would keep your quality of life and let you serve your country in the military. There are also plenty of GS jobs, and public service is public service.
I think we all wish you the best of luck, because the path you are about to take is going to be very difficult for you.