Could someone please explain what is the account payable process in SAP

First of all book Vendor invoice through T-code FB60. Enter all vendor information , i.e, invoice #, date, amount etc.

After booking Vedor Invoice go to T-code F-53(Clear Vendor). Enter here bank detail(chq#, amount, etc) and then select open items from the particular Vendor A/C in which you booked the invoice. Then Click on process Open items and clear the Vendor invoice.

1-we can create the vendor by T-code fk01

2-  from vendor invoice we can record the entry   by T-codeFB60 OR MIRO but we use MIRO when

inventory management enter the goods and print  the documents  

3-Then when we paid to vendor by cash the entry by T-code FBCJ

4-When we paid to vendor by bank check we use T-code  F-53&FCH5