Answer:
He has to learn basic first aid.
Step-by-step explanation:
He does not need to host talk therapy sessions since he is dealing with physical trauma, not mental.
He does not need a medical degree. It does not specify what type of first responder, but even EMT's do not normally have MDs.
He would need to learn first aid to administer it in the case of an accident.
He does not need to be certified in EMDR. EMDR is Eye Movement Desensitization and Reprocessing and it's used to alleviate stress for traumatic memories.