I'm relatively new also, but one of the more common methods I've heard to join was to wait for a lul or when someone has finished speaking and quickly announce your call sign. Most of the time they will acknowledge the "breaker" and ask who you are . However there are some more clannish groups, particularly on 80, who will ignore you or may even become annoyed. Just move on. It's them, not you!
In fact,there are several frequencies on 80 that one should actually avoid, IMO!
Ditto, in between calls or lulls, drop your callsign. Someone will recognize you and if they're cool will announce your call new to the gruop, ask your name and where your QTH is. If uncool they'll say this is a closed discussion or closed group, buzz off. I've encountered both in my 19 years as a ham but mostly cool people.
73, Delwyn KH6DC