The way I open /etc/hosts is to first open an xterm or some sort of xterminal and then in that terminal do:
and enter root's password. Then I use the editor vim to open /etc/hosts with the command:
whereupon I can amend the file. The terminal that you use, and the editor you use are up to you. As regards these sorts of questions, I don't think any are stupid ... most of us didn't know something sometime.