The 1st time I went to Camp Perry I asked the same thing. The best advice I got was to have my gear ready to go when waiting to be called from the Ready line to the firing line. Within 2 minutes, and it always seems like 70 seconds, your 3 minute prep period will begin and you need to use that time getting your NPA and looking at mirage. Have your sweatshirt and coat on, scope in hand, and whatever cart your gear is in, and set up quickly. Have your magazines already loaded, timer out, data book ready, adjust elevation and windage. If it's rapids, sling up. Don't forget to hand off your scorecard to your scorer, and do not forget to sign it when needed. And if you're scoring, don't forget to put your shooter's scores on the second card, in addition to the one you're using. Check your card before having your scorer hand it in, and make sure they marked the X circles. I lost one X one year, not that it really made any difference the way I was shooting, but every X and point counts.
When you sign in, take one of your ID stickers and put it on the back of your name tag. That will have all the matches you're signed up for as well as the firing point of each. Easy reference to prevent you from going to Rodriguez when you need to be on Viale, e.g. There is always someone who is hoofing it from the other range because they forgot, or didn't look at their tags.
And, as noted above, take a lot of money. More than anything, shoot safely and have fun.