Consider yourself blessed. I've never had it and frankly hate the idea of leaky plumbing and the messIs it normal to not have precum? I'm 18 and I don't think i've ever had precum leaking out of my dick
The amount of pre-cum varies a lot from man to man. I seldom get any from masturbation (although I have in the past) but do produce a fair bit when being sucked.
Producing lots or none - they are both regarded as normal.