Hello, Is it possible to add header & footer to the card? If so, can someone provide some details.

The notion of header and footer doesn't really exist as you might be thinking of in Domo. 

Some options:

Card Title and Description. Add some information in the description, when you hover over it'll display.

Page Collection. On the dashboard you could create a collection of cards. The collection has a title and a description area so you could treat that as a header/footer.

Some other options might exist if you give more details (an example) of what you'd like the end result to be like.