Suppose 4 US passport holders are going to Turkey, and have a booked, insured, round trip from US to Turkey (and back). The flights stop in Paris for ~12 hours during the day on the way to Turkey, and Amsterdam overnight for ~21 hours on the way back.
What process and fees would these people have to go through, in detail, to exit the Paris and Amsterdam airports as tourists during their respective layover periods to sightsee (and book a hotel in Amsterdam overnight)?
Additionally, what are the current steps to entering and staying in Turkey for tourists? Can I get an e-visa and handle it before I get there?
I'm sure some version of these questions have been asked before, but double checking in case there are new restrictions due to Covid.
What authoritative government source would one email/call to get a response regarding these questions in a timely manner (to double check any answers I get here)?