Women, where do you actually want to be approached by men?

I've given up on the apps and would like to try to approach and introduce myself to women in person, but I'm just honestly so lost in what is acceptable vs what isn't these days. The most obvious environment of bars/clubs is out as I don't drink or go to those places. And from my remaining understanding:

Approaching at the gym is not appreciated as people are there trying to focus on their workout.

Signing up for hobby classes to meet women is frowned upon.

Approaching in random public spaces has been pretty awkward for me, and I totally understand why. People are not socially open at all when going about their day, shopping, or waiting in line or whatever.

Do I have any of this wrong? Are there signals you give to a man when you want him to approach you? Any other advice?