and now I know why new people dont join mafia.
Welcome to the wonderful world of Multiplayer Gaming. You may notice that Game Jargon is a thing which applies to pretty much ANY multiplayer game, and you will probably want to ask people what certain terms mean.
Or you can do what most people on the internet do these days and just find and read
the wiki.
Good examples of other games with jargon are League of Legends ("going top", "Jungle", "feeding") and Starcraft [II, in these examples] ("Destiny Cloud Fist", "4 gate", "6 pool", "Forge Fast Expand"), but you can still find jargon in pretty much any place you look if it's a multiplayer game.