Resume help and tips

I'm trying to get a "normal" job this summer just for some cash and to get my foot in the door. I'm actually a STEM student but my question is should I omit details about the discipline I'm pursuing? People around me have said this might work against me if I'm looking for a job in something like retail since they'll get the hint I'm not trying to stay there for long. Also what should I put for experience if this is my first job?