If the lights don't come on on both the Circuit Playground and the LED strip, here are some things to try:
- Re-upload the code to your Circuit Playground
- Check to be sure you soldered to the "in" end of the pixel strip -- it won't work if you solder to the "out" end
- Be sure you're soldered to pin 6 on the Circuit Playground
- Make sure there are no shorts; i.e. your wires or solder joints aren't touching each other where they shouldn't be
Once you've got everything working, it's time to seal off the neopixel strips to keep them nice and safe from sweat or bumps in the night.