Setting up ansible user on multiple hosts

So I'm trying to wrap my brain around ansible. I spun up a test box to install/test ansible, created a user and generated an ssh key. Here's where the frustration starts: Now I've got to setup my ansible user on all my hosts, copy my public key, etc. I don't have a bunch of servers to manage, but enough where this is really inefficient...I'm perplexed by all of the manual work required to setup automation - it just seems counterintuitive.

There's 79 ways to skin a cat, so I know that someone has tackled this problem in a way that makes sense. How do you handle this process in your environment?

Thanks reddit!