Ubuntu is no longer chad as it pushes snaps everywhere. Real chad uses native packaging only. Lol

Just uses Akkoma or GoToSocial, setup fedifetcher or follow some relays and you can get good enough experience in Fediverse. Mastodon is literally build to handle huge amount of users so it is nowhere near efficient if used for just 1 person.

thanks…

No, you just need to go to that community while logged in with your lemmyworld account. Usually the url will become like this: http:// lemmy[dot]world/c/community@some.instance, and once you open that, you can post normally.