EC2 VM Host & Continuous Integration

On an ec2 VM, what host should we be binding to for running node.js applications? Currently, binding it to the private IP somehow exposes it to the public accessible one, but binding to localhost does not. Also is there a way to bind it to port 80 without admin perms? Not entirely a problem, but it's very inconvenient.

Separately, is there any variety of continuous integration at a happy medium between verbose docker deployment and straight-up configuring a VM from scratch while having to pull new changes manually?

Other notes: we generally used these guidelines for the front end: https://youtu.be/goiW0g7A0WE; it's the backend that we can't get to work smoothly without a lot of what feels like over-engineering.