Health care workers taking care of people with known COVID-19 wear multiple layers of personal protective equipment, including N95 masks, gowns and face shields. Gloves are changed after every interaction and then hand hygiene is performed. This combination is very effective (though sadly not perfectly), but the best PPE can be hard to find. I would obtain PPE now if you plan to work. Multilayer cloth masks provide protection and are easy to obtain.
A 30-year-old and a 60-year-old have about the same risk of acquiring COVID-19, but a 30-year-old has much lower chance of having a severe complication.
The question of quarantine is one of local guidelines, and my advice to you or your son would depend entirely on the local prevalence in your area.
While health care workers go into the field understanding that there may be some risk to themselves from taking care of sick and potentially