I’ll kill if I know how! I got rid of many apps—the Find my Friend uses surprisingly little data. I do have a weather app.
You make me happy that I got grandfathered free data. But yeah, don’t you have wifi in your home? Wouldn’t that help?
Just double tap the big button at the bottom. The screen changes to show everything that’s running like it’s a stack of paper. Just “swipe” every one of those pages to the top and it shuts them down. When I first did it it took me about 5 minutes to get rid of everything.