Hi. When I ejaculate the semen produced is clear and like watery. Also my pre cum is frothy. I have pubic hairs everywhere. However, my penis is 4.9 inches erect. Also, the glans of my penis hardly sticks out when erect. I was wondering if my penis is going to develop further or is this it. I'm 15 years old.
Average for an adult male is 5.1" erect so you are close. Your penis can grow into your early 20's too.
I'm assuming you have a foreskin when you say your glans hardly sticks out. Stretch it. Get an erection and pull down on the shaft skin so the glans helps spread the opening OR use your fingers. It may help to do this in the shower as warm water will help soften the skin. Do it as often as you can. It's normal for you to not be able to retract until age 16 or so.
Ideally, your foreskin should easily slide up and down the shaft when you are erect.