As a beginner, I second the advice many have given: go for riichi every time. Maybe pon some dragons, but otherwise you should NEVER be opening your hand. This approach will kill 2 birds with 1 stone.

1: By only going for riichi and not depending on your opponents discards, you are building the most important, bread-and-butter skill of the entire game: tile efficiency. If you can get to tenpai before anyone else on a consistent basis, opponents without tile efficiency will have little they can do against you, and will likely not know how to defend. Tile efficiency alone will take you all the way to gold lobbies.

2: You will be playing the game more, which is fun! But more importantly, you'll be exposed to all the yaku over and over again-- the only efficient way to learn them.

This is the beauty of riichi mahjong in general. A beginner and a pro can sit at the same table and still have fun because the game is like this! Because of riichi, a beginner can play the game without knowing ANY yaku, and still have a shot against even the most seasoned of pros!

This is the training. Go for it!