How are people actually finding their type?? 😭

Okay, random late-night thought, but genuinely how do people do this?
Girls on social media are always like “I want a 6ft guy who goes to the gym, is smart/nerdy, has a good personality” etc., and somehow even IRL I know people who have actually found someone like that. A lot of my friends are in relationships too.
Meanwhile, I’ve been approached by guys but never accepted because they weren’t really my type. I also don’t want to date someone from my college for some reason 😭 and if I date, I’d want it to be something serious, not just a fling.
So for the girls who’ve actually found someone they genuinely like — where/how did you meet them? Friends, college, dating apps, completely randomly?
Also, how do you tell early on if a guy is creepy or a red flag? I’ve had situations where someone seemed completely normal initially and only later turned out to be kinda creepy.
What are the early signs that make you go “yeah, absolutely not”?
Because sometimes I genuinely feel like everyone else got a handbook on finding people and I missed it 😭