If you're judging anything, learn how to do it the right way. Take the time to look on google maps to see if there are interesting tourist attractions like museums, and you could go to one of those whiles in the area during a break in competing. Remember to actually socialize with people. During my first comp, I didn't socialize at all, but in my last few I have and now I have friends so that's pog. And ofc have fun and remember it's not about what time you get it's about the cubes you solve along the way.
Like swoops said, learn the important roles of being a competitor: competing is when you are just waiting around for you to be able to solve, judging is when you are the person that calls out the inspection times and marks down the times and whatever penalties that may have occurred, running (or being a runner in general) is when you take the scrambled cubes from the scramblers and take them to the appropriate competing areas, and being a scrambler means you scramble the cubes (tips include hope you don't get big cubes, make sure you know what the solve number is before scrambling and have an efficient way to get the puzzles scrambled and handed to the runners). Know what is good to eat/do during lunchtime/whatever breaks occur. Socialize with people, and make friends. And most importantly, have fun. Competitions for the most part aren't usually too serious, so knowing that you shouldn't have to have too much pressure.
Going on with this thought, make sure you have your stuff in an area you can keep track of, not too close to other people's things. If it happens to be really packed, only take out what you need at the moment, and keep the rest in a bag with your initials or something like that.
Agree with you! Try to keep track with your cubes!
