you can see in the abaqus manual ( http://130.149.89.49:2080/v6.14/books/usb/default.htm?startat=pt05ch22s07abm13.html ) the plasticity type that you like to model and the parameters that are needed for this type of plasticity effect.
While inputting the material properties click on mechanical tab and select plasticity then you will first need the material stress/strain curve to extract points for Yield Stress and Plastic Strain or you can also import the data for the same.