Regarding deleting apps

I believe because you are using a phone with the original force touch technology, you need to use that.

Try force touching an app, and when the little options bubble pops up pops up hit "Edit Home Screen".

This should make your home screen go into the mode where you can delete apps. Nearly all the apps that aren't In a folder should be shaking with a grey x in the upper left hand corner.

Go to Settings > Screen Time > Content & Privacy Restrictions > iTunes & App Store Purchases > Make Sure Deleting Apps is marked Allow

Certain Apple apps cannot be deleted. Which apps are you needing to delete?