How do Americans say hello?

Excuse me, could you please elaborate on the various ways in which Americans typically greet each other? I'm curious to know if there are cultural nuances or regional differences in the phrasing of a simple "hello". Do they often use informal greetings like "hey" or "hi", or are more formal salutations like "good morning" or "good afternoon" more prevalent? I'm also wondering if there are any specific gestures or nonverbal cues that accompany these greetings. Your insights would be greatly appreciated.