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] |