Hey Rahul!
get down at Vasco the last stop, go to panjim n book rooms near panjim, explore panjim n church n local market in 1day.. other day go towards Baga calungate,condolium, vagartor beach n from mny place in that belt... n 3rd day return to Vasco n explore d city n than u catch ur train n return back... or 3day cum to madgoan n find dhudsagar trek as it needs a whole day