Hello, and welcome to Chess.com. There are a few different ways to play people on here. The first is to go to the open seeks page here: http://www.chess.com/echess/open_invites.html. You can also find players by rating/name (here: http://www.chess.com/members) and challenge them from their profile. Now, both of these options are for what is here called "turn-based chess." These are slow time controls where you have plenty of time to consider your options before making a move, from 1-14 days per move. A lot of people don't care for this and prefer a quicker game. If blitz is your style, you can try "live chess" here: http://www.chess.com/play/live.html. However, this feature is still in beta testing, so there may be some bugs that still need to be worked out. Of course, there are many other features here on chess.com, from videos to articles to puzzles, as well as this forum, so be sure to continue exploring and have fun.
-Omni
Help PLEASE? (I just started)