GREAT Question Peace, thanks for asking this. Listen, listen listen. Listen to everyone you can. Get a feel of how they solo first. Neil Pert, Peter Erskine, Buddy Rich, Max Roach, Dave Weckl, Gregg Bissonett, Gene Krupa, check out them all.
What you are really talking about is a skill called improvisation. Developing this skill takes many many years of practice, but the more you do it, the more comfortable you become, and you also get more proficient at it as well. Are you taking lessons? My suggestion is to get into lessons with a good, JAZZ drummer. A jazz drummer will make you much more versitile, and you will have better success.
Things to keep in mind as you develop your own style of solo. Never lose track of the tempo, always keep that tempo in mind. You can deviate a little once in a while, but don't lose track of it until you are really comfortable. Create your own "melodies" on the drums. This will help you keep the tempo as well. Lastly, make sure your solo has flow. It flows nicely from one pattern or idea, or set of ideas to the next. There are videos available that you can watch of the drummers above as well. Kevin Mahogany has a great set of educational videos geared toward the drum set player. I highly recommend you check those out at well. Maybe you can talk to your school band director and see if s/he has anything available to you as well. Most of us are willing to help anyone out. Good Luck!!