My advice would be to try and find another game in your area that you can play a few sessions with. This should give you a better idea of how your average game is run (I say average as playing styles can vary quite a bit).
If you can't do that then I would suggest getting a pre-written 1st level adventure to run. Read it through completely beforehand to get an idea of how the adventure is supposed to go and then go from there.
Don't worry too much about whether you are playing it "correctly". As long as you and your son are having fun that's all that matters.