How do I compare the Pacific island country laws with Australia? Support it with examples.

First, you'll need to do lots of research and gather pertinent information. How are you defining "laws"? Do you mean their constitutions or other organizing documents? However you decide to define "laws," you'll need to do lots of research. There are many good ideas in here, especially at the top of the search results, as well as the techrepublic.com and sitepoint.com links.

https://www.google.com/search?q=how+to+conduct+successful+searches+online&oq=how+to+conduct+successful+searches+online&aqs=chrome..69i57.9253j0j7&sourceid=chrome&ie=UTF-8

Then you'll need to narrow down which laws you intend to compare. Do you want to compare the laws that define and apply to felonies? … to education? … to health services? You'll need to be specific.

Once you have settled on exactly what you'll be comparing (telling the similarities about), then you'll be ready to search for just those laws in the exact countries you are researching.

Plan, research, revise plan, more research, etc.