

Less is not an editor, it’s a “pager” which is a read-only viewer for files, or for command output that doesn’t fit in a single screen, or whatever. Generally to control which you want programs use you set the PAGER
environment variable.
The old grandaddy pager was called “more”, as in “there’s more text than fits on the screen”. The successor is called “less”. For most purposes, less is more.
The article doesn’t suggest using Control+C. It talks about dedicated copy and paste key codes, and you can program your keyboard to map those codes to whatever keys you like. They suggest Fn+C.