Once you have disembarked from your incoming flight, you will have to clear arrival immigration and proceed to the landside departures area to re-check in for your connecting flight and get your boarding pass.
Your bags will not be checked through to your final destination. It is your responsibility to collect your checked baggage from the designated belt, clear arrival immigration, and re-check them at the landside departures area when you check in for your connecting flight.
Do ensure that you have a valid visa for entering Singapore if you require one.
If you have Scoot-Thru in your booking, you can remain in the transit area. You will not need to check in separately for your connecting flight. Find out more here.