Recently, someone I’ve been hanging out in a group with has started “copying” one of my mannerisms, might this indicate their liking me, or no?

Most people who hang around each other for any period of time will most likely do things the other does. I wouldn't read into it.

I had someone that I worked with start copying me. They also started showing up places I would go outside of work. They were also very excited to see me. It was like she was stalking me. Very creepy situation.  Tge only eay it stipped eas I moved out of town for a few months.