Providence Park is a venue in or near Portland that is most often used for Soccer
I actually didn't experience many scalpers when I went. Nothing like when I was living back in New Jersey and going to Yankees games. Maybe that's why I didn't notice them? You shouldn't have to worry. People in Portland aren't hecklers in my experience. NYC and parts of NJ? I've seen hecklers.
You can either purchase tickets from a scalper or not, they don't tend to bug you here. If you say no they won't continue to bug you.