For happening you can go yo north goa enjoy the night life and nearby beaches but crowded there is titos and various club to hangout
or you can go to casino for pubbing and drinks in panjim
Then visit calangute and baga beach(happening beach) with full of crowd and can do water sports there and Tito's lane is at baga beach and visit mambos at night as it is a night club. visit South Goa for secluded beach such as palolem beach area.
Calangute is the most happening beach in goa , 2nd number is baga beach - less crowded than calangute.. and.. I would suggest you to visit palolem beach which is on south of goa little far from Panjim but must visit beach..
For happening go to Baga, Calangute, Anjuna
for secluded try Arambol beach, it's about 45 mins from Baga but worth going or else you can go to South Goa which needs more traveling so I think Arambol is a good option.
Hope this helps!!!
If you are only going for two days, there will be wastage of time if you travel to north and south goa both. It will be good if you can stay between baga and calanguate for one day and enjoy party and then go to anjuna beach for peaceful stay.
Hey, Goa is my favorite place and if you want to just chill and enjoy the beach and food. I would suggest you to check in Backpacks panda hostel which is on Candolim Beach and beach is 150 meter walkable from the hostel. This beach is good to chill and relax because you will not get much indian crowd there. For good food you can visit German bakery in morning and in evening you can go to Jess cafe in front of new Newton on main road. For more details connect with me on my Instagram handle @aman__guptaaa .