What VSM said. Trust me, I made a living for a while stepping in for other folks on no notice - and you need to make the show yours.
And now, ask your dept head for rehearsal time in the booth. Go in when no one is in the theater and, without turning on the board, run the show - If you are calling rail cues or hitting toggle switches, put them in your hands - physically run the cues. I mean, hit the buttons, everything. And then take time to turn on the board, take the house to black and see what each light cue does, so you know what ought to happen. Watch with an eye to what's happening at the moment the cue is meant to hit, then adjust your book to reflect where it makes sense to YOU to call it so it hits on time.
Everyone else got one - you deserve a rehearsal too - take it and make the show yours.