Your first point is already done as you have chosen Sri Lanka as the country you want to visit and Kandy as one of the cities. Before you go, especially if you are going with children, you need to do some thorough research on the country. Something that people often ignore about visiting a city is a brief understanding of the local culture. What do people in Sri Lanka like, what is taboo in Sri Lankan society? Once you understand some cultural context you are ready to visit. And it will give you a whole other perspective that you would otherwise have missed completely.