Don't waste your time. There are plenty of exercises you can do without dumbbells. Maybe only a handful that you can do with only one, but just one weight sort of limits you. How much does the dumbbell weigh? Do a full body workout using your bodyweight. Such as, push-ups for chest, chin-ups for back, walking lunges, jump squats, crossover lunges for legs, glutes, hams, crunches or sit-ups for abs, etc...
Invest in a BARBELL and some plates. That will be the best purchase toward a bigger, stronger and faster body you can make once you learn how to use it.