GST settings when building

Hi, I am new to MYOB and learning to record payments made. I am building a child care centre in WA. I have been told the GST will form part of the base cost but I am not sure if/how to set the job regards the GST so MYOB deals with the GST correctly and does not require me to pay the GST to the tax department as well as pay to suppliers or subcontractors. I pay a subcontractor for work completed including the GST. I am registered for GST.

Any help appreciated.

MYOB Business lite

Wayne