VIM keys

o  to open a line BELOW the cursor and start Insert mode.
O  to open a line ABOVE the cursor.

a  to insert text AFTER the cursor.
A  to insert text after the end of the line.

e  command moves to the end of a word.

y  operator yanks (copies) text,  p  puts (pastes) it.

R  enters Replace mode until  <ESC>  is pressed.

Typing ":set xxx" sets the option "xxx".  Some options are:
  'ic' 'ignorecase' ignore upper/lower case when searching
'is' 'incsearch' show partial matches for a search phrase
'hls' 'hlsearch' highlight all matching phrases