Be the person to step up on your team. Don't just sit there and hope that your team will come together. Bring them together. Establish yourself as a leader as best you can. Don't be a jerk to people, be nice and friendly. Use pings and pay attention. Go for team objectives. Ganks are nice and all, but that tower or that dragon will give your team a much bigger boost. Lastly, learn to play multiple positions. You won't always be able to play AD carry or solo mid. And if you end up playing support, you can still make plays and have fun. That carry, that is your baby, and ain't nobody gonna **** with your baby.
And as always, stay classy San Diego.