How to control two RGB LED Neopixel Rings (16x pixels each) with Arduino UNO

Please fix your post above. You have not used code tags correctly. Delete those square brackets, highlight all the code and press the </> icon.

You should take care with this circuit. It could easily overload the Uno's regulator if you switch on too many leds at full brightness. It would be better to use a separate 2.5~3A 5V power supply for the LEDs.

Your code seems to be written for only one ring of LEDs, not two.