The shortest way to Documents once you are in Home is to type
cd Documents
Note that there is no "/".
You are trying to tell the Mac to go to a "Documents" directory that is
at the root level ("/"). There is no such directory. "Documents" is
inside "Home", not directly at root. Basically you need to understand
the difference between absolute and relative paths. Look it up! :)
--
For mail address, please run the following in Terminal:
echo 141403796329316328543255794865631358218P | dc
For location, please run the following & google result:
echo 1698946572066820688080103092351498P | dc