We have many option to create a simple file in Terminal of Linux . The examples were working in Ubuntu and most other Linux distributions.
The cat command can be use to create and view simple files.
I am a file
Will create a file and can be viewed using cat simplefile.txt command.
gedit GUI text editor which can be also used to create file from terminal using
Which will open the GUI editor
Ubuntu also have the classic vi command which can be used to create and edit file from the console
You can also get the help for each command using command –help