@marinap welcome to POA! I hope you stick around for a while.
First, congratulations to your son on getting into aviation.
Second, job well done on not letting your fear be passed on. Not sure you meant for him to go the opposite way and want to do it voluntarily, but such is life.
Third, let's talk about aviation a bit.
- Training: In general, there are very few cases you can imagine where a successful outcome is not possible. Engine failure? Not a problem, your son will be taught how to deal with this. How to work in a crowded airspace with other airplanes around? Your son will be covering this as well. Flying in clouds where he can't see the ground? Your son, although not supposed to do this on purpose at the private pilot level, will get some training in this as well.
- The aircraft: Aircraft that are used for training are required to be inspected every 100hrs by a certified aviation mechanic. Every inspection, every repair or work done is recorded in a logbook. This means that the aircraft will be much better maintained than most cars on the road. Your son will be taught to inspect the aircraft before every flight to make sure it is ready for flight. This includes both outside and inside the aircraft, engine compartment, plus checks of the engine itself before departure.
Fourth, a couple of resources for you:
- Free online private pilot ground school.
https://fly8ma.com/courses/2021-free-private-pilot-ground-school-pilot-course/
This will cover the same material as what your son will be learning in his ground school.
- FAA publications.
https://www.faa.gov/regulations_policies/handbooks_manuals/aviation
There are a lot of flying publications by the FAA and they are available for free download.
An earlier poster suggested the Pilot’s Handbook of Aeronautical Knowledge, that can be found at
https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/phak
You can either download the whole book (top link on that page), or peruse individual sections
I'm going to stop there, but again, welcome and congratulations to your son!