Shell’s built-in command usually do not have man pages, and you can try something like this:
And you will get something like this:
No manual entry for cd
But what if you still need help for a command like
cd, you can use help
<p class="codigo">help cd</p>
Change the current directory to DIR. The variable $HOME is the default DIR. The variable CDPATH defines the search path for the directory containing DIR. Alternative directory names in CDPATH are separated by a colon (:). A null directory name is the same as the current directory, i.e. `.'. If DIR begins with a slash (/), then CDPATH is not used. If the directory is not found, and the shell option `cdable_vars' is set, then try the word as a variable name. If that variable has a value, then cd to the value of that variable. The -P option says to use the physical directory structure instead of following symbolic links; the -L option forces symbolic links to be followed
Another option you have is to read the man page of the shell you are using, as example.