Yes, you are in puberty. The pubic hair is a clear indicator.
You'll get more hairy as you get older. Everyone develops differently so don't compare yourself to your friends.
An erection is NORMAL. You can get them for no real reason. As you get older, you'll learn to "control" it more.
The thick milky fluid sounds like semen. It's normal for the tip to be sensitive as it touches things. You'll outgrow that as well.
You're very NORMAL.