A new server greets you with a black window and a blinking cursor, and it is normal to feel that one wrong keystroke could bring it all down. The reality is friendlier: day-to-day work runs on a small, learnable set of commands, and the same handful come up over and over. See where you are, look at what is there, move, read a file, restart a service. Learn those and you can run a server; the rest is a help page away.
The mental model that unlocks Linux: everything is a file, arranged in one tree that starts at /, the root. Configuration is files, logs are files, your website is files. Once you know where things sit in the tree, you know where to look.
Examples use Ubuntu and Debian, the most common server distributions, but the concepts transfer to any Linux.
Type every command yourself on a throwaway test server. Muscle memory beats reading, and you cannot really break a box you are allowed to rebuild.
