i know its easy to say but don not ride above your limits, it sounds like you got all day, dont crash in your first few laps and breack something u cannot fix at the track.
bring spares, even if you dont think you will need it bring it there is nothing worse than saying 'i carnt ride cos this is broken, i got a spare at home but i didnt think il need it' and a spare engine to if you have 1 there is nothing like rebuilding a engine at the side of a track after the cranks let go on the first lap.
make sure your bike is in tip top condition, check everything before hand clean the carbs and bring spare jets tyre, pressure gauge, zip ties and duck tape

eat lots of high energy foods and keep well hydrated race tracks really tack it out of you, you dont think it but its hard work.
the rest should come natural, just get a good feel of the track before u start to push hard.
if you are using road tryes drop the pressure down race tracks and road pressure = crash, ask a trye man there, or other fellow riders.
and last of all have a good fun day
_________________
if dont fall off every now and then your not trying hard enough