As far as I know, the current best practice for language learning is called Krashen’s Hypothesis or Comprehensible Input. Basically, we can learn a language best by hearing words that are slightly more complicated than what we already know. I am learning Korean and there is a nice YouTube channel where a guy makes videos of himself playing games and he talks about what’s on the screen at different levels of complexity. You could look for something like that in the language you want to learn.

This is the answer. Look up the Facebook Pixel and Like Button. Putting them on a site lets Meta track your activity across the web, even when you’re logged out or don’t have an account. I’m sure Twitter, Reddit, et al. are doing the same by now.