create a code to execute to fill data in textfield.
ex. I click water.
water contains code to fill textfields.
name: Water
amount: 10
quantity: input ur quantity
you can add description (optional)
put a button to add this item to datagrid or store in model then datagrid.
pass this value to model to store arrays or direct to datagridview.
personal recommendation: I highly not to modify how things looks. use the default theme stick to white plain for fast efficacy.
Just arrange them in a way to look more plain & simple.
It just needs to work that's all. even with no design everything will be nice if arrange accordingly.