Depends on what you play best. I play cash and am sticking to a 40BI rule when moving up. Meaning I have 40 buy ins for the next level of stakes before I attempt to move up, if I drop down to 35 buy ins I'll move back down, win the 5 buy ins back at a level I know I can beat and then take another shot. Different games require different bankroll management, if you are a tournament player then it is recommended that you have more buy ins at your disposal.
Seeing as you are in the cash section I'm going to assume that you are going to be playing cash, if you decide to go with tournaments =
https://www.cardschat.com/forum/tournament-poker-59/
Bankroll management will also depend on your skill level, 20BI is accepted as a standard rule for beginners but if you are still learning the game I would seriously consider having 30+. Other factors such as how well can you handle a couple bad beats and if you tilt easily should come into the equation.
As for poker lingo, do a google search.