If you want to interface serial shift register 74HC595 with Raspberry pi then visit http://www.bristolwatch.com/ele2/74HC595_cylon.htm. This site gives you all the necessary codes.
Prithvi, to use shift register with raspberry pi, wire up the data pins 1-4 and LED’s. Next wire data pins 5-8 and the LED’s, followed by other pins like Vcc, GND, clock, not clear input A & B. (Note- The input wire can be at high or low level, depending on what needs to be set, and then the clock is turned high or low.
Each bit to be sent is set either high or low, and the clock is turned high, and then low.
If you want to send another bit to the register, set that bit on the input, and then click the clock. )
Dani has already mentioned the initial connections. Just flow it. Here I will explain as to how it works and provide you with few links. First send 1 bit of data into the DATA pin. Then provide with a pulse at clock pin. At this point, register takes the input and stores it. After this, the second bit at DATA pin is provided, and also a pulse at SHCP so as to store the second bit. Once the 8 bits are received, pulse at STCP to shift 8 bits to the output pins. https://circuitdigest.com/microcontroller-projects/raspberry-pi-74hc595-shift-register-tutorial gives an explanation about the programme.