I used to be a giant creep. I knew I had no social skills, tried to develop some, and it backfired more often than not. For example, I knew I was clingy and unable to tell if people wanted to get rid of me. So I reasoned that I should just hover around people I wanted to talk to and make it unclear whether I was there because of them or by coincidence, so they would feel free to talk to me or not as they wished.

What helped was Internet articles like those linked above. Those actually explain what behaviors are desirable and undesirable, and basics of reading people.

I still don't know the difference between "You should go away" and "Should I go away?" - verbal expressions of these are identical. "I'm leaving, bye" and "I'm leaving, wanna come along?" are also hard to distinguish.