Judo
Teaches you to never fight force with force. If you are pushed, pull. If you are pulled, push. Use your opponents momentum and your own technique to make true power. These ideas can be used through all your social interactions.
Judo is a style where size does not mean instant victory, as true technique overcomes all.
Be confident when you are on the ground. You will learn how to gain a dominant position and protect yourself on the ground. When you are old enough, you will learn how to lock and choke to submit your opponent.
Learn the proper way to fall. No one wants to fall, but eventually everyone does. Be sure you know the correct way to fall so that you can always get back up without injury.
You will have great a great time working with great people!
And you will make friends that last forever!