You’re not wrong, but you’ve got a bit of an extreme take on it. I think you and your parents may have different thoughts on what it means to “approach” a woman though. I’m going to use “flirt” to refer to talking to a woman with intent of seeing if they would make a good partner for you and just “talk” to indicate just being friendly with someone.
it is only appropriate for a man to talk to a woman who doesn’t know when the social situation is explicitly designed for meeting strangers
No, it’s fine to talk to strangers of any gender in public. Approaching them and flirting with them is not. As long as you can roughly understand when you’re making someone uncomfortable and stop it, you’re not going to come off as a creep/predator. Stuck in a lineup in a store? Chat with someone beside you, maybe commiserate about how long the line is. If you want to flirt with them, then yes the situations you mentioned are definitely the places to do that.
(sort of an aside: whether “meeting friends of friends” is an appropriate situation to flirt with someone you just met is still situation dependent)
They are adamant that I need to learn to approach women or else I will never find a partner.
Approaching women in random public spaces with the intent of finding a partner is also a pretty bad idea. While it could work, it’s definitely creep/predator behaviour so I avoid it. It’s very likely to make them uncomfortable, since they’re just trying to do their thing not get hit on. This can easily be harassment, though I’m on the fence on whether it’s always harassment.
Personally I like to flip the genders on situations like this and ask if I’d want to be the other person in this situation. It’s worth keeping in mind that woman have way more statistical reasons to be weary/wary of any interaction with men, though. Regardless, e.g. if some woman was beside me in line and started chatting with me, I’d be fine with it. If some woman came up to me and complimented my shirt, I’d be fine with it. If some woman came up to me, complimented my shirt, and then asked for my number I’d be weirded out (I don’t know you, lady). If some woman came up to me and asked me to take out my earbuds to commiserate about how long the line is, I’d be annoyed that I’m missing my music.
I hear Lemmy is pretty good as a sort of forum, maybe you’ve heard of it?
But more seriously, I’ve found that social media platforms (even the fediverse ones) tend to limit connections to surface-level. I personally wouldn’t rely on them to find people to talk to. But if you’re looking for communities who share similar interests, it’s very good at that. If you’re looking for individuals, the next best thing is sliding into someone’s DMs to have a more focused one-on-one conversation. I’d recommend against doing that without some other interaction first (it looks scammy).
In case you want to chat, my DMs are open.