BRF Rule Creation Information

Hello Experts, I would like to get some information of how create a BRF Rule for Request Type (Change, New User, Terminate/Delete).

Could you please provide some information of how does it works, I have already create a rule and in an SAP Guide give some actions to create initiator rule. But I am stuck at this point so I would like a step by step to create a rule for NEW CHANGE AND TERMINATE USER.

Thanks a lot for your help.