Covid samples are collected by rasal or pharyngeal swabs , it is very safe and quick, you might have irritation for a minute or so .
Sample collection method is the same for RTPCR and Rapid antigen test
Advantage of RT- PCR is the results are more accurate, however Antigen test , you'll get result on the spot.
Next Steps
antibody test is not specific and hence adviced not to get tested for diagnosis