i → Insert mode. Type ESC to return to Normal mode.

x → Delete the char under the cursor

:wq → Save and Quit (:w save, :q quit)

dd → Delete (and copy) the current line

p → Paste

hjkl (highly recommended but not mandatory) → basic cursor move (←↓↑→).

Hint: j looks like a down arrow. :help <command> → Show help about <command>. You can use :help without a <command> to get general help.

1. a → insert after the cursor

2. o → insert a new line after the current one

3. O → insert a new line before the current one

4. cw → replace from the cursor to the end of the word