I don't have any resources beyond recommending searching something like "linux command line basics" in your favorite search engine, but I do have some advice. You have to conceptualize it at a higher level than "shell commands:" the shell is just a way to run programs, and pass arguments to those programs to do what you want. The names and parameters of most common programs like ls, touch, mkdir, etc[1]. will become second-nature over time. There's no fast-path to learning them, you just have to force yourself to use the command line in your daily workflows.
They look like 'commands,' but what's actually happening is the shell is searching directories that are listed in your $PATH environment variable, for an executable with the name you entered. Diving more into the mechanisms of how the shell works is potentially educational depending on your learning style.
Starting with Arch, you're setting yourself up for a bad time, since you'll be learning both basic command-line knowledge and how to configure linux from scratch. Ubuntu or Fedora might be better places to start. OSX will suffice for a unix-y environment, but there are definitely some quirks that won't translate nicely to linux-y distros if that's the direction you want to go.
Larger objectives you mention like starting a server, the first principle is still "what program can I run (i.e. call from the shell) to do what I want?" And in this case, it would be the program that manages processes for your system. Not sure what Mac uses, but many linuxes are using `systemd` nowadays. If you search `systemd basics` it will give a good sense.
[1] Shells also have built-ins (like cd) and you can learn a lot about the intricacies of them by doing actual shell scripting (e.g. "bash tutorial"), but it sounds like you're mostly interested in getting your feet wet with the basics before diving into scripting. Although it's a nice way to round out your knowledge.
