No matter how hard I try to read up on this or ask for people’s help, I cannot tell when another person is attracted to me. And I feel bad about it, because what am I supposed to do if I want to do anything flirtatious or date? Trial and error? Just try it with anyone I think is attractive until I learn what the patterns are? Sounds like a quick way to be seen as That Guy. Even if I just ask, that’s still a pretty forward move, letting someone know I think of them like that. So I really do not know what to do there, and it upsets me.
Are you hetersexual?
Generally, you’ll know if girls are attracted to you if they don’t avoid you and make themselves available to your attention. They’ll give you every opportunity to talk to them. The more you’re interacting with them ‘organically’ (ie your interactions aren’t mostly just you going out of your way to talk to them) the higher the likelihood they like you
The same can also be said of platonic friends.