Hey Smedwicks,
Before I make any beginners recommendations, since I think the game is really balanced, with everyone having tools and useful access to the game's systems, I'd ask what kind of playstyles you usually like in fighting games. Grapplers? Shotos (fireball, anti-air)? Charge characters? Speedy characters? Tricky characters?
Normally, Athena, Terry, Kyo, EX Iori, Robert, and several others are the first ones to come to mind for beginners recommendations, since they're Ryu/Ken esque.
Team order, once you get used to utilizing drive cancels, EX, and other meter management, will become important, but there are downsides in some characters able to use meter better than others. The first thing I'd work on is making sure whoever you use can fight and win with no drive (blue) or stock/power (orange) at all; from there, it only gets advantageous.
Other than asking questions here (which you still should), if you haven't checked out the wikis for the game yet (DC's -
http://dreamcancel.com/wiki/index.php?title=King_of_Fighters_XIII), it's a good place to help you build yourself up.