those are not the kind of beaches you see on porn videos. Not full of hot women and men fucking around.

Yeah i always say the first thing people need to know about nudism is that the #1 practitioners of it are wrinkly old people 🤣. If you can look past that, then you're an actual nudist and not just an exhibitionist.

if I barely know them I feel some shame. I know it’s stupid but that’s how I feel. I can’t explain it

Not stupid at all - it's a question of safety/feeling safe, both for you and for the other person. You never know how they'll react.

Once my GF in high school had a classmate tag along when we were out in the woods together, and I think seeing me strip down for skinny dipping unprompted made her uncomfortable - probably the last time I will ever be so careless in who I'm nude around.