Hi,
I am a noob trying to build a Bluetooth speaker using Arduino.
Need help with using 2 Music reactive led strips with one Arduino pro mini. Want the strip to show increment/decrement of 2 leds when volume up/down button is pressed.
Many thanks in advance
OK, where's your cod thus far?
Hint: Read the instructions, notably point 7. 
I am a noob trying to build a Bluetooth speaker using Arduino
On a hiding to nothing there.
What sort of Arduino?
They are eminently unsuitable for the task and will only work with a low quality. And you need a Bluetooth module capable of being in the audio mode, many cheap ones are not.
You will pay many times more than just using Bluetooth audio receiver module.
Well, it seems the OP is not expecting the Arduino to perform the audio conversion which would indeed be pointless, only to perform the display.