I can recommend tourist places to visit, it is a wonderful place btw!
Top spot to Visit:- Marina Bay Sands Sky Park. It is at 56th floor. You need to buy a costly ticket to go up there. But the view from there is just awesome. Time to visit must be evening only, never in peak daytime. So go in early evening, stay for 2-3 hrs till nightfalls. Take the view of pre-evening, sunset, and sundown nightfall. There are snacks restaurant too at up top there.
Next, you must experience the light and musical show happening just down, in “Gardens by the Bay” area. It has specific timings, I think 7:30 pm and 8:30 pm, for 15 mins each (find about the timing online). Don’t confuse it with the light show that happens on water (Spectra show) in Marina Bay Sands area. Both areas are nearby. But “Gardens by the Bay” where Supertree are there, that’s the one to attend for the musical light show. You sit among trees, among the large “Supertree groves” and you enjoy the light show with its accompanied music.
Post that, you can walk around the Marina Bay Sands area, before climbing on that Sky Park, you can also get photos taken at the iconic Singapore Tiger statue- named Merlion. There is a Casino too there, just in case you want to gamble- entry there is allowed only with Passport and with some deposit money. All these can be done in single day on 2nd half of the day.
Apart from this- 1 full day trip- Beaches- Sentosa Island resort. There are 3 beaches there, one is having pool side stuffs etc with living accommodation etc too. If you are a wealthy guy, earning in crore plus, I would recommend staying there in the resort one full day to enjoy.
One more must visit, and this one you can visit late evening too- Clarke Quay- what a lovely place and so happening. Lots of pubs, musical places around, you can just walk around and enjoy doing nothing, or just sit by the water, or even take a boat ride, and if you are a booze guy, drinks…