Is the size of my penis too small? Boys stare in locker room

Possibly. The size of your penis cannot be changed or altered by medications. It will continue to grow through puberty so do not focus on the size before then. If by chance you are still concerned about having a small penis, you will need blood tests to evaluate your hormone function and if low, medications may be needed but this usually not needed.
Size variable. A penis can look very small if you are obese because it will be partly hidden within the fat pad. Boy's penis is normally much smaller before puberty. Some boys and men have penises smaller and larger than others. You should probably consult with a urologist (pediatric urologist or endocrinologist if < 18 years).