I'm a New at Terminal operation
 

Hello. Can you suggest me a link to an easy-to-understand instructions about Terminal or Shell operations? Thanks a lot!

Here is a list of common shell commands:

Linux Commands

See TLDP's Bash Guide for Beginners

And a BASH reference pdf to download and keep :)

I would suggest Linux Command as a good starting place. For some more advanced usage I can recommend Rute User's Tutorial and Exposition.

Hope this helps