Welcome to this forum. You will find good information and helpful people here.
You say you just acquired your car. Well, before doing away with the synthetic oil for good, may I suggest that you do a search on engine oils here? I think you will find a majority opinion that synthetics are the best you can do for your engine.
As to availability, Mobil 1 synthetic seems to be sold everywhere, auto supply stores, Wal-Mart, etc., almost anywhere motor oil is sold.
However, if you are determined to return to dino lubrication, flushing is not required. The oils are compatible. A normal drain and refill will be okay.
Have a good day and good luck.