Set by default a search engine which doesn't track its users
Hence, not DuckDuckGo: https://forums.whonix.org/t/duckduckgo-now-fingerprinting-visitors/6497/1
In the short term, I suggest to switch to Qwant (kinda the French DDG, except seemingly not compromised yet): https://www.qwant.com/?q=%s
!q
.
In the long term, I suggest we host a FLOSS search engine, like a GNOME Searx instance, though Searx instances tend to be blocked by search engines like Google, resulting in abysmal results.