> Easy if you know where to look. If you end up in the wrong sub menu you might simply search the web for instructions.
Actually, at the very top of the home page of the settings app is a search bar. If you type in anything reasonable (default, email, mail) then one of the first 2-3 results will be “default apps” or “default email”.
Maybe 8/10 people in your family circle would benefit from reading the published user guide for their device. That doesn't take technological proficiency, just reading.
