I'm a white belt who is competing in a submissions only competition in 3 weeks. Keen to know if you guys have any tips on training / drills to do in the coming weeks to help prepare. This is my first competition so I'm not sure what to expect but keen to get the experience & learn.
For your first competition, my advice is not to put a lot of pressure on yourself to win. Go into it as a learning experience. There are going to be a lot of unknown stressors that will drive your adrenaline up. Where do I need to warm up? When is my division? What mats will we be on? When do I step on the scale? When do I step on the mats? And so many more.
Because there are so many little things to learn, you will be even more stressed than you will be in the future. It will help if you go into it with two goals: learn the process, and have fun. You can worry about winning gold later. If it happens, it happens. Frankly, it is more likely to happen that first time if fun is your focus.
Just for your safety and longevity I would drill injury prevention from some causes of injury that are prevalent among overzealous white belts. I see a worrying amount of injuries at white belt matches from sloppily jumping closed guard (hyperextends knee) and slamming out of closed guard, armbars and triangles. Those I would prioritize. Afterwards there are some others like sloppy tani-otoshi (knee hyperextention), rear suplex onto head/neck and slamming out of back control that do occur as well but less prevalently. I would suggest getting familiar with those too when you have the time for it.
Make sure you're not cutting weight (or not much) for the comp. You want to be hydrated and be able to have breakfast. Don't smash lots of Gatorade or sugary drinks. Pack healthy snacks. Don't make any drastic changes to your diet. Train at higher intensity with partners you trust to not go "full ham" as my son would say.
The focus needs to be on fun and learning :)
Good luck!