How do i add extra notes for Customers

How do i add extra notes for Customers like
No Refund & No returns accepted
Received in good condition etc

Custom fields

Custom field to add extra column as it shows.
I want to add extra notes on bottom of page left corner

That is only one possible use of custom fields. Read the Guide:

Searching and reading the Guides should always be your first step when you have a question.

Custom field doesn’t serve purpose what i am looking for !
I want to add fixed notes printed on all invoices eg. Thank you for visiting us !! etc etc

1 - Go to Setting > Custom Fields > Sales Invoice “New Custom Field” and create.
2 - Then go to Settings > Form Defaults > Sales Invoices and enter the required text into that Custom Field.