If it is just emails that you want to keep private Proton mail is a good one.
Duckduckgo.com only keeps Google from seeing what you are doing, whoever is providing the WiFi etc still knows your every move.
I suspect he's out of the country and wants to watch Wimbledon.
https://www.techradar.com/news/wimb...to-watch-the-tennis-free-online-from-anywhere
DuckduckGo is https, all a wifi provider or ISP can see is that you are connected to duckduckgo. They cannot see the url nor can see what your searches are, whether that's the search or the results returned. If you get SSL certificate errors then they are trying to intercept the traffic and you should disconnect at once as it is not a secure connection.
Yeah, they can see your searches because - at least by default - they use GET not POST, so your searches are in the URL eg https://duckduckgo.com/?q=Cyclechat+&t=h_&ia=web
And even if you find a work around, your internet provider will also see the URLs of any sites visited.
They cannot see the url, that is encrypted