After reaching Panaji you can hire a cab or auto for candolim but I would suggest to rent a bike or scooty which are easily available there, it will cost you around 350 to 500 rs a day.It is true that candolim beach is peaceful beach and people love it but it is also a good spot for watersports. If you are adventurous and don't like crowd then candolim is the best beach to visit.
After reaching there you can ask anyone about the watersports agency. When we visited candolim there was only one agency available which provided 5 activities namely parasailing, jet ski, banana ride, bumper ride and water scooter ride. These all have different prizes but if you want to do it all, combo pack will cost you around 1400 to 1800 rs. Out of these activities parasailing, banana ride and bumper ride are awesome. There are some eateries also so you don't need to carry extra burden of food items. Accommodation will not be a problem as many hotels are available there and If you love to party then you can find many night clubs in candolim area whose charges vary according to popularity of the club. If you want to enjoy it to the fullest go with the friends.