Terminal

After Installing Ubuntu, you are mainly going to work through Terminal, therefore I will discuss about basic commands in Terminal.
First of all, in order to open a new terminal, you can go to dash home at the top of the side bar at the left of your screen and type terminal and then click on it or you can click Ctrl+Alt+T
After you opened a terminal, you can check the current working directory by typing pwd. 
 In order to see what files and folders are in this directory type ls. Remember that there might be some options for the command that you are typing, you can read about these options through manual pages, e.g. type man ls. You are able to move up and down in the manual by Up and Down arrows of your keyboard and you can search by typing the favorable text after slash e.g. /full. You can quit the manual by typing q.