Dear High School Graduate,
Congratulations! You made it, you survived high school, and you graduated! The future is bright and also kind of scary. It's okay to be scared though. Even though I'm only a few years older than you, here's some things I wish I knew when I graduated as well as wisdom to bestow.
I guess the biggest thing that I learned is don't stress yourself out trying to keep up with and in touch with all your high school friends, especially if you were just casual acquaintances. You'll soon find out that many people that you thought were really good friends you were only friends with because you saw them so much. There will be a lot of people that you lose touch with, and that's okay. Take this summer to make memories with them so that even if you lose touch you always have the stories and memories to tell.
If you have a job, work your butt off this summer. When you get to college you'll find out that textbooks, activities you want to do, food, and other miscellaneous expenses add up pretty quickly. You may not be able to work when school starts, so save up that money now. Don't ruin your summer for the sake of work, but try to work as much as possible. Take that extra shift when you can and help your coworkers out. It's also impossible to be bored if you're working.
Spend time with your family. You really will miss them once you get to college, and they will miss you too! Hang out with your siblings and hang out with your parents. Try to have quality time together before you part ways. Don't take the evenings spent sitting around talking or watching Netflix for granted.
When you get to school, get out of your comfort zone as much as possible. Join the club that sounds cool, try out for that sports team or play that you are interested in, and get involved in the things that interested you in high school. Did you really like being in band or choir? Find out if your school has a non-audition ensemble. Chances are they do. Go to sporting events, even if you aren't the biggest fan of sports. Chances are it'll be a lot of fun. Take a look at Greek life, even if you are absolutely positive it isn't your scene. There are plenty of Greek organizations that are dedicated to service or special interests like music or science.
I guess what I'm trying to say here is make the most out of your summer. If you can't get to everyone's grad parties, so be it. Take the time and reflect on the last four years while you get ready for the next four years.