I know how you feel! I reckon most everyone here would be so many little ducks lined up for easy shooting if this were a realistic combat flight sim, but, this is freelancer. I suck, too.:)
That said, the wikis got a list of general tips and tricks, but this doesn't cover old tactics for caps, or evolving tactics for same with the advent of turret steering.
There's always a few folks that go to conn willing to help you out.