My wife is from Venezuela, but technically she's half Colombian, as her mom is Colombian. The main Venezuelan dish is the arepa, made with a specific corn flour brand from Venezuela called Harina P.A.N. which luckily can be found at Fred Meyer. And yes lots of plantains too. But other than that I don't have too much advice to give cause yes unfortunately there aren't any dedicated Latin American stores except for Mexican stores. There is a nice food cart pod in SE Portland called Portland Mercado. I've never eaten from the Colombian food cart there (Qué Bacano) but I know the owners of the Venezuelan food cart (La Arepa) and I highly recommend it. Could maybe be cool for you to take your son and his girlfriend there when all this craziness ends.
I'll look for Harina P.A.N. corn flour at Fred Meyer. That's where I bought the plantains. He and I were there, and I said add anything you want for your birthday, and he couldn't find anything except the plantains. (The main present was 6 months of online college, thousands of dollars.) When he returned to her, he texted that she was very happy to get them and was cooking them right then. For you unwashed masses who don't know all about plantains, they look like bananas, and are more vegetable than fruit. Everyone knows this. That's what he told me today, anyway. Now that I think of it, he might have been putting me on and gotten some free bananas off me. I used to live in Hawaii. I know about ugly bananas.