I had a lot of fun pulling back the covers and having a look at how it works. I even created a skel project for when I want to spin up more functions. The included Makefile should show you everything you need to know about how to create, package up and deploy an app.
The only part I didn't catch at first which caused some digging around was the VPC/Networking set up. If you want your function to talk to other AWS resources (ec2, s3), you need to associate it with a VPC. That VPC will need to have a public and private subnet. The function should reside in the private subnet, and there should be a nat gateway in the public subnet. Finally make sure you have a route from the priave subnet to the nat gateway.