You're heading to paradise, I love Singapore, I have only explored Orchard Rd, never had to venture further than there because there's no reason.
Four floors is opposite the Hilton, start about 7.00pm and goes all night, it's an education to sit outside and watch all the gorgeous girls come to work.
My best advice is to get one from there for the night, don't pick up of the street or be conned into going to "their" special place for a drink, it will cost you heaps. These girls are on hourly contracts, what you pay for them you can get some one for the entire night and a good wake up next morning.
Keep wallet passport phone etc in. Hotel safe but that's standard all over the world.
It's dearer than Thailand but it is very exciting, one of my favourite places on earth, enjoy