vim has Normal and Insert modes. Press i to insert text and Esc to return to Normal. :w saves, :q quits, :wq saves and quits. /pattern searches, dd deletes a line, yy copies it, and p pastes it.
vim Basics
vim file.txt
# Modes
# Normal mode — default (press Esc)
# Insert mode — press i to type
# Command mode — press : to run commands
# Essential commands
i # enter insert mode
Esc # back to normal
:w # save
:q # quit
:wq # save and quit
:q! # force quit (discard changes)
/word # search
n # next match
dd # delete line
yy # copy line
p # paste