if you're a beginner, please, dont even try to look at the multiplayer code!
I hear that all the time but it's wrong. The A7 multiplayer tutorial is pretty good and understandable even for a beginner. When you're ready to write a normal game, it's no problem to write a good and fast multiplayer game.
Just my two cent. Don't let someone discourage you! Multiplayer with A7 is very easy.
Writing a MMOG of course is something different, for this you need a team and should definitely not be a beginner.