Hi Sandeep, if you already have your travel documents like flight ticket, hotels and transportation then you don't need anything else. Indians travelling to Bali for tourist purpose do not require a visa to stay up to 30 days. Apart from this and based on my experience( as i was there in june 2019 ), you must visit to Gili islands especially Gili trawangan. If you have any other query then please reach out to me.i have done Scuba diving also in Gili
In addition to whatever Kaif said, don't miss to carry your passports(on a lighter note :) ).
I spent around a week in Bali, you can check out my posts for details, the tips might help you in saving some money there.