The problem you have selected to challenge is just a bit more complicated.
Cell phones are never really fully off. At least they are able to see and respond to an on/off button, and more than turn on, they wake up.
So in addition to hacking the idea of first, second and thrice button presses, and short and long, you'll have to manage the power with some extra ordinary circuitry and processor states.
I suggest you get a prototype working that just has an on/off switch, and a pushbutton for speed control one-two-three.
Then add long presses that simply light an LED so you know you are programmed correctly to see the long press, even if it doesn't turn off you device just yet.
Then look into low power and sleep modes, and how to get an Arduino to sleep soundly whilst waiting for that wakeup call.
Don't be intimidated, low power is fairly straight ahead if not a place for a total noob to start.
Read the link below as if you understood what he's talking about! It is a slog, but he has complete workable examples and good tips for how to fix up the hardware for low power:
HTH and please, step by step.
a7