Fossils, they show us many different things, for example dinosaur bones show us how they acted in the past, and links to what animals that are still alive today. Second, is that fossils, human fossils turn into Carbon to which makes diamonds and coal to help us in everyday life. And finally, Fossils show us how living things have changed over the years.
I hope that helps, to be honest I'm not good at science either but I hope you get better soon..