Tips for fresher in SAP ABAP consultant

Hi Receiver,

Let me tell about myself first,

Completed ABAP training, and

Joined as fresher in a role of ABAP Consultant.

Nowadays, I am facing more issues from the functional side like

Sales order, Purchase order, Invoice, Document...

What are these things, I am not able to understand anything..

Kindly assist me

Regards,

Sender