It’s not a bad idea if you are genuinely interested and it doesn’t put you in an unmanageable time crunch. You absolutely should cultivate hobbies of some sort outside of your scholastic work, whether they are part of a club or not. I just wanted to make sure you weren’t adding them for the sake of adding them because someone told you that was a good idea, that’s all.
It’s not that uncommon to have a resume for an intern candidate with little to no experience. Experience that isn’t relevant is only weakly helpful anyway. Your grades will be more important, and most likely research experience would be a more relevant job to have for the resume anyway. Also, keep in mind a part time job is going to really torpedo your free time for those non-engineering clubs you mentioned (and engineering clubs).