For me, the Linux community at the programming(dot)dev instance is very helpful!
Always check the relevant wikis. Yes, some of them aren’t very well-written, but most are very good. Look at the wikis for your distro, the software you want to use, etc. Even if you don’t use Arch, the ArchWiki is a very good source with steps that can apply for most distros!
You might also want to check out the channel “LearnLinuxTV”, they make fantastic tutorials for setting up various distros and self-hosted services.
I will also recommend installing “tldr”, which is basically manpages for dummies, showing you the essential commands and their parameters. “Tealdeer” is a Rust-based client for tldr that is available on Arch (unsure about other distro families)
And of course, many forums are good too, but note that many of the bits could be outdated (always check the date of the posts and the version number!)