VMware Hands On Labs: look for: HOL-1821-05-CMP - vRealize Orchestrator - Getting Started
Blogs: Start with mine https://www.vcoteam.info - be sure to look at the other blogs that I link to as there are several that have additional tutorials and have more recent posts.
Videos: Automating with vRealize Orchestrator series by Brian Watrous
It's very useful. Please share more video if you have.