[tmtvl]

Depends on what you're gonna be doing with it. If you're mainly working with HTML, CSS, maybe some Bash scripts, you can just open it up, work your way through the (IMO excellent) tutorial and you're off to the races.

That said, if Emacs gets its claws in you you may, like me, lose a fair few evenings and weekends just playing around with various packages and customization options because it's just so fun to tweak.