What are the steps to join the navy after high school or during high school?

Im a junior almost a senior and idk what to do after high school and my brother is in the navy as an electrician. So i was thinking of joining the navy just as a last resort bc idk what else i can do plzz help me!! Btw idk anything bout it thats is why im asking for help. And i have never taken rotc or know anythng bout it