The Outlook traveller has a nice article on 10 good walking trails in Goa. 

North Goa

The Calangute walk through Calangute village, the Saligao walk, the Arpora walk, the Assagao walk , the Aldona walk and the Divar Island walk.

South Goa

The Chandor walk, the Colva coastal walk and the Utorda walk.

read more on the Outlook Traveller website