So I just purchased premium for one month but I know I probably won't use it for more than a month since my game library isn't all too big. So if I cancel my premium now will I still have my premium benefits until July 29th? I know it sounds like a dumb question but I assumed that for a subscription and cancelled it and lost my perks.

You will keep your perks until it expires even if you cancel it, follow the instructions here.

Cheers!