It would take months to cover the entire island but if you can spare two weeks you will be able to visit some of the best places on the island
What to pack
Sri Lanka is a tropical country, so it is warm and humid across most months, so you need to be prepared for the weather. Pack comfortable clothes like shorts, shirts, t-shirts and tank tops with slippers, sandals and walking shoes. Bring a hat, sunglasses, sunscreen, and mosquito repellent and you are good to go.
1st Week
There are so many places to visit in Sri Lanka but during the first week, you can explore the south of the country. Visit Galle, Hikkaduwa, Unawatuna, Colombo, and other cities where you can enjoy the sun, sand, and beach and cherish wonderful memories.
2nd Week
For the second week, you can visit inland perhaps, Anuradhapura, Polonnaruwa, or upcountry where you can explore Kandy, Nuwara Eliya, and Ella.
Preparing to head back
Truly Sri Lanka and other blogs will be able to give you details about good ways to end your vacation, but you can always head to Negombo, relax by the beach and then take in the sun and the sea before you head back to your homeland.