Most companies that hire for search engine evaluation have multiple projects available to work on, so the exact work you do might vary. However, search engine evaluation in the traditional sense involves analyzing queries that regular people like you and me might type into Google or Bing search and then determining the best possible results to match up to that query so that users have the best experience possible using a search engine.
You could also opt to use existing websites for making money. These include both active income and passive income methods. For example, you could sell some used items or invest in creating some digital designs that then can be sold on merchandise. Again, devote a sizable portion of your time to passive income so that you can slowly build up earnings that will arrive on autopilot without any extra added effort. 
How much will you make? I think my best month with Google AdSense was almost $5,000 over the last ten years. That amazing month blew my mind since it was actually near the beginning of my blogging journey. When you go from making zero to $5,000 in a month, that will rock your world. For me, it also got me even more excited because I knew there were other ways to monetize.