The thing i notice with first timers, is
They dont have their gear ready intime for their lift, = stress = missed lifts, and head all over the place, be ready BEFORE its your turn, and ensure your trainer wrapper is focused on you..
eat.
make sure you understand the rules, usually at a first timer novice comp they will explain everything to you that is required, and expected.
Get all the important stuff sorted asap, openers, registering, pin heights etc, then go socialize, eat, piss, warmup what ever.'
Keep looking at the boards, the lifting order may change form round to round.
Its your first meet , making weight is not important, breaking world records wont count usually, so I would keep your lifts conservative,
what you can triple as an opener
gym PB??? if your training is on track as a second
than a small jump to your third, i saw people adding 20+kg for their third lift, and they bombed..
Nothing stuffs your first meet more than bombing on your first or second lift, really puts you in a bad mind set afterwards.. you want to leave that first comp, feeling like you nailed it, if you think you have bit left it makes you hungry to do so at your next comp..