Using a charger brick with multiple voltages for a ARGB LED strip

I have little knowledge about electricity, but I have a little project scheduled.
So I'm planning to buy an ARGB LED strip, a WS2812B to be exact. I plan on using a ESP8266 to controll them, and to power them to a certain extent. But if I want a longer strip or more LEDs it's recommended to use a power supply.
I have a charger with a USB port which I thought I could use. I'll would want to strip a USB cable and use the wires from it to connect to the LED strip. But I would like to know if this is possible with a cable like that?

The other question that came to my mind is that the charging brick I ought to use has multiple voltages on it: 5v - 2a (which I need for the strip) and 9v - 1.67a. Does the brick know what voltage to use? Or do the chips in the les strip know this? Or will I break it when I do this?

I really hope someone can help