All people working in Australia have the same basic workplace rights and protections , regardless of citizenship or visa status. Contracts or agreements cannot take away your rights. Under Australian workplace laws, the Fair Work Ombudsman (FWO) protects and enforces the rights of visa holders.
Prior to commencing work, you should also ensure that you have received a Fair Work Information Statement from your employer. This will make it easier for you to understand minimum workplace entitlements. A copy may also be found through the link below.