Lately I've been experiencing pubic hair growth above my penile area and red bumps behind my scrotum. I'm worried about telling my parents. They may overreact.
Congratulations. You are in your adolescence now and probably in Tanner's Stage 2. The pubic hair you've gained is just the start. I suspect the bumps on the back side of your scrotum are where your hairs are starting to push out of the skin. It takes a bit for the opening to widen to let the hair freely come out, so the hair pushes up the skin a bit as it is growing, making a small bump. It will flatten out eventually.
The time to be concerned is if the bumps are itchy, big, or red as these might be signs of an infection.
Since your father went through adolescence himself, he would be surprised at all that you have started. Your mother also has experienced the female form of adolescence, so she would understand in general what you are going through. I don't think you have to fear them overreacting if you want to mention that your body is starting to change.