Some people are very self conscious. The first time I got naked in front of strangers was at a naturist swimming club. I thought it a bit more private than a public beach.
I was extremely nervous while I queued to get in, there were about 15 men and only one woman who was a lot older than me waiting. I had visions of being stared at by a group of men, fortunately at the last minute another younger woman turned up and she had been going there for a few years, the older woman was her ...... and they went together most weeks. I then felt more comfortable knowing that if it was a bad place to be they would have been unlikely to have continued going.
Turns out quite a number of them were gay, so if anything they were more interested in checking each other out than me. After a few visits it didn’t seem unnatural at all to be naked in front of others.
I have since been to other swim clubs, camp sites and beaches. People have generally been respectful, the only places that have been a bit creepy have been Spanish nudist beaches where there seem to be a lot of men sitting in the dunes per on women. I would suggest women avoid that sort of place for their fist public nudity experience.
And to answer your next question, very little sex or even hooking up happens in naturists locations. In all the years I have been to them, I only ever once had an invite from anyone that turned out to be a sexual encounter. A couple l got friendly with from a swim club that had a boat invited me on a naked day out on their boat, during the day they asked if I was only interested in the naturist lifestyle or did l indulge in other activities outside of the cultural norm? That was their way of asking if l would be willing to have sex with them.