Two Flats On One Ride And Another Newbie Mistake

Rode from Long Beach to Fashion Island and Corona Del Mar. Had two flats along the way. After repairing the first flat I noticed that it was difficult to pedal. It felt like I was pedaling in mud. I figured that I did not pump enough air into the tire. I struggled to push 12 MPH working hard for five miles. When I finally stopped at a bike rental shop along the way, I noticed that my brakes were not centered and I was pedaling against my brake pad!!! Won't make that mistake again.

There is only a few millimeters clearance between the brake pad and the tire rim.

Wonder why I'm having so many flats? Any ideas Jim? Maybe it's time for new kevlar tires, and some slime self-sealing tubes.