It shows the time control of the game that's being played. for example, "1" says the game is a 1 minute bullet game.
Time
so i would 1 minute to make a move? they usually have two numbers though...(example 10/0 or 5/4 or 30/0) but the line is straight up and down
No, "1" means you have one minute for the whole game.
For example, "3/2" means, you have 3 minutes for the whole game, plus 2 seconds is added to your clock on each move you make.
http://www.chess.com/learn-how-to-play-chess.html
Yes, click the "players" tab, and look at the "action" coloumn. If a player is not playing a game at that moment, you'll see a "Play" link next to their name. Clicking on Play means challenging them.
If you want to challenge the friends you have here, you can click on the friends tab and do the same.

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