Im a rookie, need help!!!

[Rattlehead]

A lot of it just comes with practice...you will learn an 'instinct' for dogfighting, which only practice can give you.

Two basic tips would be to always maintain speed and altitude.
Don't turn too hard as this bleeds off speed.
Don't dive to the deck and linger for too long...always look to grab altitude whenever possible.

As noted above, learning deflection shooting will be of tremendous benefit as well.