iPhone 7 is stuck on Apple logo

This is called a boot loop and sadly there's not much you can do that doesn't result in you erasing the phone. Here's how to fix it if you have a Mac or PC, note that this will erase everything on the phone but if you have an iCloud backup of it, you'll be fine.

1. Hold the power button, and both the volume buttons at the same time until you see the recovery mode screen
2. Plug the phone into a mac
3. Go to finder and the iPhone should be in the sidebar
4. select it and follow the instructions on the screen to fix it
5. It'll tell you to either restore from backup or set it up as a new phone. You'll want to restore from backup unless you don't have a backup.
6. after it's done, it should work well as new!

the recovery screen looks like this

See→If your iPhone is stuck on the Apple logo - Apple Support