how do i level up?

using the search funtion would have netted you 6 threads with answers... but

lookhere

this will answer your question

Shake yer booty

By giving away games. Games that have not been bundled give you more "points" towards future levels. You get the full value for any non bundled game (depending on the value of the game itself), but only 15% of the value for a bundled game. Check this list to find out if a game has been bundled or not.