
https://www.onsemi.com/pdf/datasheet/mm74hc595-d.pdf
https://www.onsemi.com/pdf/datasheet/mm74hc595-d.pdf
You should connect 8 LEDs; perhaps a Pmod might also work.
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | sclrn | q[0] | |
| 1 | ser | q[1] | |
| 2 | rck | q[2] | |
| 3 | srck | q[3] | |
| 4 | G | q[4] | |
| 5 | q[5] | ||
| 6 | q[6] | ||
| 7 | q[7] |