If you think that you're more interested in ACOL or Precision, you might want to find a book or two on these systems to help you out or visit LinkLand which contains links to sites where you may download information on other systems. There's one other aspect of bidding, quite related to the system, but independent of it in many cases. This, more or less, makes sense. You've judged that the partnership doesn't hold enough points to reach game and the partnership has quite a few diamonds. Therefore you want to stop in 2 and play the hand there.
Conventions are partnership agreements.
BOTH partners must understand what they're saying. For this reason, these common systems, particularly SA-YC, are typically played on online bridge servers such as OKbridge, Bridge Player Live and the Gaming Zone. Some will say that SA-YC is not a good convention card to learn. Some will say that it has its problems. Some will say it's too complicated.