Play money games are a great way to learn the game. However, if you're looking to improve, you should go ahead and make a deposit and start single-tabling a 2NL table.

The problem with play money poker is that there is no incentive to play well. If you lose your chips, you click the reload button and more play money is given to you. In a cash game, if you bust your bankroll you're done until you deposit more of your hard earned dollars.

Cliffnotes: Play money poker isn't "real" poker. If you have a solid understanding of the game, make a deposit and hit the 2NL tables.