If you want to learn how to use the CAD design tools CADENCE to design integrated circuit, then the best way may be to receive some training or follow some tutorials as proposed by Sadeque. If you want to be able to design analog integrated circuit you have to be able to analyse manually the basic building blocks of analog integrated circuits which are the basic amplifier circuits, the differential amplifiers, the current sources and current mirrors and the biasing networks.
If you are able to manually design a basic op amp you will smoothly ramp to the design CAD tools as they only aids the designer.