Data load from SAP ECC to SAP BI

Hello Gurus and Experts

                 I am new to BI and I m almost struggling to find a step by step process in loading data from SAP ECC to SAP BI through generic extractors from VBAK. The Problem is I can create an Infopackage for full update and loaded the records.(Lets say Upto this step 100 records are moved to PSA)

Then I create a sale order in ECC which is a new record that has to be transfered as delta record.

Now my questions are:

Am I correct if I moved the initial records into PSA with Full Mode InfoPackage?

Should I create another infopackage for delta records with Delta Mode or to change the update mode of the infopackage created earlier for Full Update mode?

Should I create a new infopackage every time to load the delta records?

Does separate DTP has to be created for Full and Delta updates?

Please dont be frustrated if my questions are pointless or childish

I would be glad if someone demonstrate the solutions in steps

Thanks in Advance

Karthik