If you don't have anything else to do besides tennis. Sleep at 10-11p.m and wake up at 6:00a.m(or whatever time the sun rises). Go to the courts and work on your footwork and your serves. If you have a wall then use that practice your groundstrokes, volleys, smashes, etc. Find friends who are early morning people and play with them.
I'm in college currently and we usually just play after classes end when it's not too unbearably hot and play for a good 3 hours.
If you're seriously going to play D1 hire a coach and work your a.$$ off, or else some foreigner will take your place on the team. If you just want to play tennis for competitive fun then play club college tennis, the universities in our state play tournaments with each other monthly at different schools.