If you're not into parties than Go for South Goa..
They are lot peaceful and less commercialised and crowded
Some of the Best Beaches in South are 1. varca beach 2. Benaulim 3. Palolem 4. Agonda 5. Cavelossim
North Goa best beaches are Morjim and Ashvem beach. These are serene and less crowded. WE recently stayed in Whitewoods resorts and Spa in morjim. Its a new property and they have both the options bungalows an wooden cottages very near to the beach . Tou can check out our youtube video for more details: https://www.youtube.com/watch?v=MxbS_1b4boE&t=13s
Southern goa treats you with beautiful beaches...if u like to explore u should stay in palolem and take scooty rides to turtle beach, cola beach. i haven't seen better beaches in india so far .
South Goa is the place to be , palolem beach to be precise, just the right crowd not over crowded as baga or calangute, also not as sleepy as agenda which is just 15 mins from palolem also a great beach. great beach, great sunset moments even can go for morning boat rides with the fishermen to c dolphins.
As you said you are not a party animal... best beach is agonda beach for u. ull definitely love agonda beach. thank me later. 9690575804 this is my number. is u ask will share some pictures.