One would expect https://ubuntuforums.org/ but that forum is so ancient, it’s still asking for ICQ IDs in your profile. Not sure how many are using it. I still asked there but I’m not sure if it’s the best location.
AskUbuntu maybe.
AskUbuntu.com by far. Many years ago it replaced ubuntuforums.org for support queries. As others have pointed out, the current discussion place is discourse.ubuntu.com. But for support questions AskUbuntu.com is the best place and the best format because it’s easy to find the questions and the answers from within and via search engines without having to sift through tons of discussion responses. Anything that’s already answered becomes easy to find for the next person having this problem. Sometimes when I find the solution to a problem I had that wasn’t obvious, I add a question and answer it myself for others to find. Of course you can ask here as well. ☺️
!Linux@lemmy.ml will help you for sure.
LMAO, good one!