A good introduction to Kriol can be found in this readable article: Explainer: the largest language spoken exclusively in Australia – Kriol.
Written by Greg Dickson and published in The Conversation in 2016, the article covers essential information such as the difference between the terms ‘Kriol’ and ‘creole’ and talks about the growing recognition of Kriol in recent decades. Definitely worth a read if you have only recently heard of Kriol.