How can we create the login class separate and utilize for the whole project instead of login steps

Hi Amna 

Yes, you can copy the login steps out to a new keyword test (click the plus symbol next to the KeywordTest repository in Project Explorer), paste the operations (or record the operations), then you can drag-and-drop that keyword test into any existing test. Or, you can organise your Execution Plan to perform the login test, then run the subsequent tests.

Hope this helps,

Mike.