Is there somewhere where this information is explained in simple English for a non-techhie?
You could try a web search – there are tons of WordPress tutorials out there, or possibly one of these YouTube videos (have not watched them personally)
https://www.google.com/search?q=youtube+creating+a+menu+in+wordPress&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a