We'll use the preattached wires from the LED strip to attach to the power supply. The red wire goes to + and the black to -.
We'll add an additional wire from the + side of the power supply to VOUT on the Circuit Playground, and attach the black wire from the NeoPixel strip GND to Circuit Playground GND. Finally, we'll attach the white wire from DIN on the NeoPixel strip to A1 on the Circuit Playground.
If your setup has more than around 250 lights, or if you want to turn the brightness ALL the way up with your lights on full white, you will need to add a second power screw terminal to the other end of your strip as well (red to + and black to -) and connect power at both ends to avoid strip brown-out.