How do you remove apps?

See >>> How to delete apps on your iPhone, iPad, and iPod touch - Apple Support

If you are unable to remove Apps, you need to check your ScreenTime restrictions:

Settings > Screen Time > Content & Privacy Restrictions > iTunes & App Store Purchases > Deleting Apps - ensure that this permission is set to Allow

See if this helps

https://support.apple.com/en-us/HT207618

There are certain built in apps that you can also delete, but some are considered mandatory to the device so cannot be deleted.