A notepad with to-do plan lkst for the place you are going to visit. (though i know mobile phones have been dominate, but still if anythings with phone). A first aid box with some medicines used commonly.
A trip to Bali with round tickets may cost you around 45-70k depending upon how early you book your flight tickets, this is including approximate overhead cost in Bali. Flight tickets 30-50k depending upon how early you book them. Visa on arrival for Indians $35 Hotels are cheap considering ₹ is stronger in Bali. Good Scooties can be rented for as cheap as ₹300-500 per day. But during the stay in Bali you may find food is little expensive and shopping places as well. P. S. It is easy to bargain there at prices so as to cut down the prices.
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
It depends from where you are. search for the local treks nearby. Don't directly jump towards famous himalayan treks. If you are from Maharashtra then you can try Sinhgad Fort ,Lohgad Fort , Koraigad Trek. ,Rajmachi Trek