How can I tell that a certificate is a root certificate?
You may want to refer to Lists of available trusted root certificates in iOS on Apple's website. This resource also provides links to lists of root certificates for specific versions of iOS, macOS, watchOS and tvOS.

Typically, to remove a root certificate on an iOS device one would follow this process:


Open Settings
Tap on General
Tap on Profiles (NOTE: if the Profiles screen is empty then there’s nothing to delete)
Select the Profile you want to delete
Tap on Delete Profile
Enter your passcode
Tap on Delete again to confirm the deletion


Based on your screenshots and tags it's clear you're referring to a device that is controlled by a Mobile Device Management (MDM) process. If you can't remove the certificate(s) you want to with the above process you will need to contact your employer/school/etc to seek assistance.