If you have 2 days to visit Singapore, here are some recommendations for things to do. Please note that these are just general recommendations and you can pick and choose which activities you would like to do and in what order you would like to do them.
Day 1:
Start your day at Gardens by the Bay, where you can see the famous Supertree Grove and the Cloud Forest.
After that, head to Marina Bay Sands to take a picture of the iconic skyline.
Next, take a walk along the historic Singapore River and visit Clarke Quay for lunch and shopping.
In the afternoon, visit Merlion Park and take a picture of the iconic Merlion statue.
Finish the day with a delicious dinner at one of the hawker centers like Lau Pa Sat.
Day 2:
Take a morning trip to Sentosa Island, where you can visit Universal Studios, S.E.A. Aquarium, and Adventure Cove Waterpark.
After that, walk around the colorful streets of Little India and try some of the local food.
Next, visit the Buddha Tooth Relic Temple and Museum in the Chinatown area.
In the afternoon, take a visit to the National Museum of Singapore to learn more about the country's history and culture.
Finish the day with a night stroll through the Orchard Road shopping district.