Proz.com is a site where you can get paid to translate all kinds of documents, including files and even conversations. The site provides you with an opportunity to list your services as a translator. They offer opportunities in Spanish, German, Italian, Chinese, Arabic, Japanese and other languages, and specialize in legal, medical, technical and other fields.
Keep in mind though, you don’t need a website to do sponsored content since you can also get paid if you have a lot of social media followers. My wife has a pretty big Instagram following, and she gets all kinds of sponsorships. Not only does she get paid in cash, but we get a lot of free stuff, too. We’ve received free rugs, free lights, and free carpet cleaners. She only promotes things she loves though, so this strategy works really well for her.