If you're going to work in a registered club or hotel and your duties involve gaming machines, you must complete competency training in the Responsible Conduct of Gambling (RCG). If you don't have valid evidence that you've completed the RCG training required for working with gaming machines, you could be fined.
You'll need to be trained by a Registered Training Organisation. You can find an RTO online through the Liquor and Gaming NSW website.
Once you've undertaken your training, you'll need to Apply for an RSA or RCG competency card.