I\'m most often finding myself having to work with plain old vi on minimalistic terminals that tend to act differently than the vim on big distros, and so the behavior trips me
I am guessing you want to use o to "open" a new line. However I have provided some ways to insert text via vi
It should be noted that vi/vim's cursor sets on top of a character not between character like most editors.
i insert text before the cursora append text after the cursorI insert text before the first non-blank in the lineA append text to the end of a lineo begin a new line below the current one and start insert modeO begin a new line above the current one and start insert modeS/cc delete the current line and start insert.c{motion} delete {motion} and start insert mode. Read as changeC Delete from current position to end of line and start insert modes remove character under cursor and start insert moder replace one characterR start replace mode. Think of it as overwriteFor help on any of these command type :h {command} so help on A would be :h A