Create/Edit a file in Terminal

# cd Directory
# touch file.filetype
# nano file.filetype

enter content

ctrl-o (/save)
ctrl-x (/exit)

# cat file.filetype (/displays content)

//
NANO(1)                     General Commands Manual                    NANO(1)

NAME
       nano - Nano's ANOther editor, an enhanced free Pico clone

SYNOPSIS
       nano [options] [[+line[,column]] file]...

DESCRIPTION
       nano  is  a small, free and friendly editor which aims to replace Pico,
       the default editor included in the non-free Pine package.   On  top  of
       copying  Pico's  look  and  feel, nano also implements some missing (or
       disabled by default) features in Pico, such as "search and replace" and
       "go to line and column number".

EDITING
       Entering  text  and  moving around in a file is straightforward: typing
       the letters and using the normal cursor movement  keys.   Commands  are
       entered by using the Control (^) and the Alt or Meta (M-) keys.  Typing
       ^K deletes the current line and puts it in the cutbuffer.   Consecutive
       ^Ks  will  put all deleted lines together in the cutbuffer.  Any cursor
       movement or executing any other command will cause the next ^K to over‐
       write  the cutbuffer.  A ^U will paste the current contents of the cut‐
 Manual page nano(1) line 1 (press h for help or q to quit)