Most unix commands are lower case. Unix is terse. You'll rarely get feedback as to the progress of a command. Unix is flexible. Switches can be used to change the way most commands operate.
Online help is available.
There is one fake man page. You must leave a space between the command and any switches or arguments. Without any argument, returns to your home directory. Make a new directory. Many things that you don't think of as files actually are treated as files.