The fit must be right between you and the merchant who is going to benefit from your promotional efforts, or it simply won’t work. The easiest way to begin with affiliate marketing is to select an affiliate network. Many affiliate networks exist, some which are tied to well-known companies like Amazon, Google, and Apple, while others specialize in specific types of products and services.
If you live in an area where Uber or Lyft operate, why not become a driver? If you're looking to make some short-term cash, you can definitely rake it in by working for one of these popular car-hire apps. As long as your vehicle fits within the specifications of their program, and you have a clean license, you could do this on the side, especially if you're in a crunch for cash.
If you have pop-ups and optins on every page, I would have to think that it would be a lot harder to convince someone to link to it. Especially since the pages where you have your optins (and probably receive the most traffic) are probably the same pages that you have your best content on as well that you'd be hoping to pitch in your outreach campaign.