Q: The Pages app is displaying lines I didn't create

Apple actually has a community for iWork for iOS applications. You have posted in the Pages for Mac community, and these applications are entirely different.

Hi Kem,

I've requested a transfer of your question to the iWork for iOS community.

Regards,

Barry

A screen shot would be helpful, as would the specific template you are using. In the meantime, check the style of the paragraph immediately above and below the line to see if it includes a border