My son did an accelerated EMT program that met 8+ hours a day, during COVID no less. You should search your local area for these accelerated programs.
The first thing your son should do is get CPR/AED(Adult, Child & Infant) certified.
My son is currently a Tactical Emergency Casualty Care(TECC) certified law enforcement officer working to become a SWAT medic. At the rescue squad he volunteers at he works as a Duty Officer, Technical Rescue Team member, EMT, EMT Preceptor and Driving Preceptor.
If you have specific questions feel free to message me as well.