Hey Zainub, THINGS TO DO IN GOA : 1)North Goa Beaches : Anjuna, Baga, Calanguate, 2)South Goa Beaches : Colva, Butterfly, Palolem, Agonda, Netravali Lake 3)Fort Arguada ( Movie 'Dil Chahta Hai' was shot here ) 4)Dudhsagar waterfalls ( 2.5 hours, 60 km from Goa) 5)Activities: Scuba, Prasailing, Mandovi River cruise ( Casino and party), A boat ride for Dolphin watching 6)We enjoyed all nights in Goa by drinking and sitting on beach and returning to hotel room in morning 4-5AM. Then next day started wandering again from 1PM and at last in evening back to beach. Hope this would help you.
You could go to Agonda beach. It's at the southern most end of Goa, almost near Karnataka border. It's very peaceful away from all touristy stuff. The journey from north goa to south goa is also quite enjoyable.