Can I get some help choosing condom size based on your experiences?!?

I'm 18 and about to lose my virginity soon, so I need to find tge right sized condom to be prepared, but I don't have the money to go on a condom spree so I font want to hear "try various ones on".y is 6" long and 5.5" girth. The normals fit pretty snug, with the extra length rolled up at the end. Should I move up to magnum for my girth? Or will the length on those leave too much rolled up