@mickeychicky your profile leads me to believe you are in Florida. Depending on where you are in Florida, you can get a free test from the NOMI Health sites (https://nomihealth.com/fl). They do both PCR and Rapid tests that are approved for cruising, and no questions asked about the purpose of the test when you register. I have used them for testing when there were several people in my immediate office who had undiagnosed COVID and were in the workplace (but obviously once they knew they had COVID, they stayed home). The rapid tests have results back in 15-30 minutes and you can download/print the results. The PCR tests take about 36 hours to get results back (in my experience). There is information at the NOMI link if you scroll down towards the bottom that may answer some of your questions/concerns (even those you may not know you have).
As for the test itself, like others have described, it's like a long-handled Q-Tip that is placed in your nostril and swabbed for a few seconds, then removed and placed into your other nostril (that part just kinda grosses me out, but it is what it is). When someone else is doing the test for you, they usually have you wear a mask and just pull it down so your nose sticks out, tilt your head slightly back, and they swab you. Some places have you swab yourself under their supervision, just depends on where you go (like Walgreens was drive-up, stay in your car). The NOMI site in our city is walk-up, so you park, then go to the window where they scan your pre-registration code, ask you if you want PCR or Rapid (or both), then they get it ready and send you to the next window. It's all outdoors in a parking lot.
I hope this helps.
My biggest concern at this point is we sail in 32 days, so I am beginning my extra-vigilance about social distancing again so we still have time that if we are going to get Covid pre-cruise, we have time to get it, get well, and still sail, but it won't be long before we are too close to our sailing date to be sick.