The White Sand Beach is located close to Candidasa Bali. To reach here, you can drive north from Candidasa, and it will take about 20 minutes to reach the destination. It is also called as Perasi Beach and there is no public transportation available. The only way to reach here is by renting a car or bike.
You can go snorkeling and yes swimming can be done without any fear. However, make sure you check out the sea condition.