Another doctor here--NOT OFFERING MEDICAL ADVICE (just summarizing literature as of this date).
1) Prevention--get enough sleep and eat a healthy diet--low sugar, starch, and processed food; high green vegetables--the darker and more bitter the better. Vitamin C 1,000 mg once or twice a day, zinc glycinate (sometimes called "chelated") 60 mg once a day, and turmeric 300-600 mg once a day--all safe unless severe kidney or liver disease. Selenium glycinate--YOU NEED TO KNOW YOUR LEVEL BEFORE STARTING IT. If your level is in the upper half of the reference range, you don't need it and it probably won't help. If your level is below this, it may help prevent COVID-19--your dose will depend on your level.
2) Monitoring--get a no-touch forehead thermometer and a pulse oximeter. Get baselines of both. If you develop a temperature 2F over your baseline or over 100.5F or cough or shortness of breath, call your doctor. If your O2 saturation falls below 92%, call your doctor.
3) Home treatment--stay hydrated (Gatorade [regular, none of the varieties] or Pedialyte--these should be kept in every home). Breathing exercise: take five deep breaths in, holding your breath each time for five seconds. On the sixth deep breath, do a big cough. Repeat that cycle once. Do this often. Lay flat on your stomach as much as you can otherwise. Your doctor may prescribe an albuterol inhaler (or xopenex--like albuterol but does not increase heart rate). It is unlikely that he/she will prescribe an anti-viral or steroid for home use (there is conflicting literature, but both may improve outcome in severely ill, hospitalized patients). There is also conflicting literature on hydroxychloroquine as preventative and/or treatment.
4) Hospitalization--all of the above plus O2 and IV therapy in an intensely monitored situation. Cooperate as best possible to try to avoid need for intubation and artificial ventilation. Outcome with artificial ventilation is much poorer than without. This is likely due to being so sick as to need artificial ventilation, but artificial ventilation itself may play a role.
Please note that I am NOT OFFERING MEDICAL ADVICE (just summarizing literature as of this date).