Warm ups and attempts: The Strength Athlete has a free meet card that helps you plan your warm-ups once you figure out your third attempt. I've used it before, highly recommend.
I like to go ~90% of third attempt as my first, ~95% for second, and then 100% for third. Of course if everything feels way heavy, you can go lighter, and if it's super light, go heavier.
I usually don't have the same food as normal on meet day. With traveling, etc, I don't get the opportunity to cook eggs and sausage. I try to go with carb-heavy stuff, a bagel and cream cheese and an apple for example. During the meet, I bring Gatorade and candy to snack on. Protein powder also. I've brought PB&J but never eaten the sandwiches so I've just stopped.