Cleaning up and securing better privacy settings? Looking to better secure my account and clean up data from it.

I’ve just about had it with much of social media. I’m starting the slow process of removing information from Facebook profile before greatly scaling back my use of Facebook.

Anyone knowledgeable about whether it’s useful to unfollow pages, remove photos I’ve uploaded, etc? Can I request that Facebook delete data? Or do they get to keep it forever?

How can I better set up my privacy settings so that my account is less valuable to FB advertising? Do I have to just remove myself altogether, or can I continue using the app for the things I like about it?

Thanks!