A good way to know if someone is acting interested? Also, How do I show I am interested?

Question

I am not very good at spotting general signals and "hints" from people that I meet socially to determine if they are interested in meeting again.
Anyone have some good advice on how to tell if someone is acting interested. I am hoping for some good info on any general clue that should make me realize they are interested, or even better so, if they are NOT interested!
Is there body language, topics of conversation or questions that people generally do or ask ...?
ALSO, What is something I can say or do that would show that I am interested in them?
I am a 22y/o female, so any input from the gents would be appreciated (as well as from any savvy women out there!).

Thanks
UTTERLY CLUELESS

Answer 1

Talking to you and not going away, smiling, blushing, touching you asking for your phone number or ask you out are some signs they are interested. If they go to the bathroom and not come back they are not interested. If they don’t talk or smile at you the same thing.♪