Despite its creeptastic name, Stalkscan can show you what kind of information people can already search for. For starters, you need the full link to a person's profile. Enter the profile URL in the search box and the site will give you quick links to a bunch of searches for things like that person's pictures, videos or likes. If you're searching for yourself, you'll see private photos that are only visible to you and those you've shared with, but it's still a handy way to see what people can search for.
https://stalkscan.com/
https://stalkscan.com/