Went up to a girl at the gym

I’m 18M and I was seeing this same girl at the gym for a few weeks and I thought she was pretty so I made eye contact with her a few times then for 3 weeks after that first time we would make eye contact often not always me looking first, so today she came same time but did 2 random exercises and started walking on the tread mill, I did see her looking at me a few times so I figured I would try talking to her

I went on the treadmill beside her with 1 in between because I didn’t want to get too close and look weird, but anyways I start walking too to give myself time to build courage and when she glanced at me I said “how’s you day going”, she looked away so I was hoping she just didn’t hear me because I couldn’t see her ears because of her hair, she was looking in my general direction and I say excuse me but then she looked the other way instantly, so I just left since my workout was done anyway

I thought she was at least somewhat interested because yesterday I looked at her and she looked at me then a few seconds later we both look away, I looked back instantly and see she was smirking

Did I just read the eye contact wrong and what could I do better if I see someone else at the gym or just in general. I do know girls don’t like being approached at the gym but I’m graduated so I don’t know how else I would see her