In south goa u should stay in byke hotel its a reasonable in price for a person and its a connect with the beach so u can enjoy the shaks near by hotel .
You can search on different apps like mmt, Goibibo or go directly and try some guesthouses. in my knowledge, at Baga beach you can find pg flats too. if you are in a group of four or five people it would be a good deal.
Hey John, Here are few for you :- Hostel Zostel in Calangute Backpacker panda in Candolim Little India beach cottages in Baga Sai Palolem beach cottages Nikita Residency in Calangute Anjuna palms guest house near Anjuna beach Morjim sunset guest house is also good to stay in goa for reasonable rates ... Happy Travelling Bro!!!
Try holiday beach resort or 360 at Candolim.. beach is very close by. also you may find many oyo hotels. Airbnb etc. but if you wanna enjoy the Goan feel you can check out Home-stays which are amazing in Saligao sangolda Baga calangute pernem ashwem areas and in South Goa as well