I'm a guy. Well, I was in the same boat. Many people in high school and college understood the subtle social cues that I could not see. I hear that people with a hint of autism have trouble with these subtle social messages. But, after I've been giving relationship advice for a while, and see what people consider "flirting", I can totally understand why they are so confused. Which is why I don't flirt much.
If I want to date someone I talk to them, make sure they aren't crazy (in a bad way). If it's working out, I just ask them out on a date. It's that simple. So, when I give advice to someone, I say "Don't flirt. Just ask them out, and use the word "date" so they know exactly what it is, and no one gets hurt. No one's been hurt too much by direct communication."
Now that I'm in my early 40s I understand more of these cues, plus I have been dating much more.
I have a long time interest in psychology, specializing in relationship dynamics for 30 years.
(Please note, we give the best advice we can based on the information given in a post. For better advice, please include the age of all romantic partners.)