You can semi-protect yourself by going into your phone's settings and turning off location and microphone for Facebook. Facebook likely uses both of these to suggest ads to you. Its why you see nearby restaurants in your ads. And its also why you see things that you've talked about in your ads. They can only get this information through their apps (Facebook and Messenger), so that's why they always push you to download the apps instead of using your browser. My suggestions is to delete any social media apps and just use your browser, even if its a bit more inconvenient. To be fair to Facebook, other sites do it too. I've gotten oddly relevant ads through both Reddit and Amazon before as well.

I have a friend who works for a company that buys/sells data for a living. So this is the advice I got to avoid some of your data being collected. Its kind of scary how much data you give away through apps. Ever wonder why all of your social media and messaging apps are free? Because they collect and sell your information. Nothing you do/say is private, even if they tell you it is.