Login as admin or accountant
Select product category sub menu from inventory menu
Then click add a product category button and fill all fields and submit
Select product sub menu from inventory menu
Then click add a product button and fill all fields and submit
Select warehouse sub menu from asset inventory menu
Then click add a warehouse button and fill all fields and submit
Select supplier sub menu from inventory menu
Then click add a supplier button and fill all fields and submit
Select purchase sub menu from inventory menu
Then click add a purchase button and fill all fields and submit
Select sale sub menu from inventory menu 
Then click add a sale button and fill all fields and submit