Hi Ratan,
please start with the standard docu in help.sap.com and reading the standard documentation of the IMG activities.
A good overview is in the SAP PRESS book by Martin Gillet.
If you use self services (and that's most likely) then you need to be familiar with the basic configuration procesdures for the technology you use, i.e. WebDynpro ABAP, Fiori or UI5 in general
Any specific questions after that, I"m sure the community can help.
kind regards
Sven