Hi Ramesh
If you have Business Knowledge of WM and Technical Knowledge of ABAP. No need to have any other.
In ewm as an ABAP there are many different things you can do Like as below.
connecting to other system.
BAPI enhancements
badi and XI integration and RF and many other.
No need of project exp its enough u understand ABAP with any Business. But ur effort mater when you join EWM as to understand Warehouse Business.
Regards
Suraj