I need to set a 36-character, one column margin but can't figure out how to do that. Also, I'm trying to turn on line numbering but can't get that to happen. I've gone into
"Line Numbering," ticked the box that says "Add line numbering" and "continuous" and clicked "Okay," but I'm not seeing them. Do I have to be in a particular view?

I'm using Microsoft Office 365 on a PC, Windows 10.

Thanks for your help.