Notes won't open on iPhone 6

I want to be able to use and store Notes on my phone (not iCloud).

I can only see the word 'Folders' on an empty screen with the word 'Edit' greyed out in the top RH corner.

Under Settings, the 'Default Account' in black but has 'On My iPhone' greyed out.

There is a green enabling button below this for "On My iPhone" Account, but the green button is greyed out as well. (See photo below.)

When I click on 'Default Account' it goes to a new screen that says 'On My iPhone' in black with a blue tick on the RH side.

Further down on the previous 'Accounts' screen under the heading 'VIEWING' there is a 'Lock Screen & Control Centre' section that has a line for 'Access Notes from Lock Screen'. I don't know if that has anything to do with my problem. When I click on 'Access Notes from Lock Screen' it gives three options to select: 'Off', 'Always Create New Note', or 'Resume Last Note'. No selection seems to help my problem.

When I click on 'Default Account' it goes to a new screen that says 'On My iPhone' in black with a blue tick on the RH side. I don't want a password for Notes, & I don't use a passcode to access my phone.

Thank you for your time reading this - I hope someone can help. Sue