You'll become an apprentice first. Check online for schools in your area.
Some places will say they are looking for experienced plumbers only but apply anyway. They might be willing to train you especially if you have a good personality.
As far as a truckload of math. I'm not a plumber but I rocked with a lot of them for a while. If you can learn how to use a tape measure you are good to go at the base of things. A lot of it is measuring pipe length and using chemicals and the necessary couplings to keep them in place. Remember that plumbing arose from and continues to primarily focus on removing waste ie unclean water from a residence and allowing a way for clean water to get in. There will be codes to adhere to. But all this will become known through your training.
I say go for it.