What do you need to check out before hand? Course architect, Playing yardage, weather conditions, and past tournament scores.
Why is course architect important? Different designers will have different characteristics throughout their courses (Donald Ross- inverted saucer greens and Nicklaus- dog leg rights with a lot of bunkers). This will help you tailor your training leading up to the tournament. On a tight golf course preparation, you will be playing your home course more effectively by playing the rough as a chip out.
Playing Yardage- It is important to be familiar with the length of shots you will have into the greens, short courses more wedge work and long courses more hybrid and wood practice. Will all the tee shots be drivers off the tee or will there be a mix of clubs? You also need to use google maps to have a plan before the practice round to know what clubs to hit off the tee. Mapping out the widest area on each hole makes it more efficient in the practice round and training leading up to the tournament.
Weather Conditions- You need to know ahead of time will it be cold or hot, rainy, or windy. All these conditions will affect your packing and training leading up to the tournament. In cold or hot environments, you need to pack the correct clothes for the day, thermals and layers for cold days and breathable cloths for the heat and extra gloves. If you know there will be rain be sure to pack extra gloves (especially rain gloves), an umbrella, zip lock bags to keep stuff dry, and your rain gear. The wind preparation has more to do with the training leading up to the tournament. A great deal of time spent working on trajectories, shot shape, and start lines will help your preparation.
Past Tournament Scores- This is not the end all be all, but mentally getting ready for the scores to be high or low can help. If the scores are low, I would practice more from the forward tees of my home club being comfortable to scoring being under par. If the scores were high I would spend my time playing two ball worse ball matches learning to recover.
Summary- Tournament golf is an important part of junior golf and the college recruiting process. It is always better to be prepared when entering a tournament than showing up blind.