So lately I have noticed two girls staring at me in the gym.

First girl, she looks good, but has lot of weight and is trying very hard to get in shape. Initially she used to stare at me and somehow she started talking to me. I haven't talked anything but she smiles whenever she sees me and I too smile. I don't want to make a move here

Second girl, joined a couple of days back and I caught her staring at me atleast 3 times in these two days. She looks cute and I want to make a move. I know how to keep a convo going and asking things etc but how should I ask her out?

Also, I have a big crush on one girl in the gym, but she ignores everyone to the point that she won't even make eye contact with anyone in the gym. I somehow want to approach her and ask her out. Someone asked her if she has a bf and she said she doesn't like having bf, but I believe she just don't like that guy