I have tested out Ansible recently for Server admin, the experience is nice but it may take time to understand the whole eco-system.
There are a few concepts to understand before hand
Ansible uses SSH to execute Python Code in the Client machine, therefore, the Client needs to install OpenSSH and Python by default. It looks up Python 2 by default, a custom parameter is needed to instruct Ansible to use Python 3 instead. Everything makes sense if follows this direction.
Ansible Playbook is the script that drives the client machines to work, there are a lot of build in modules in Ansible. Worst case scenario is using the shell script module to write all commands. In this case, the script may only execute once, and may have side effect if execute more than once.
Ansible Collections and Roles are pre-built extensions for Ansible, a role usually serve one function, for example, managing sysctl.conf service or managing Grub. A collection is a collection of Role that may have multiple functions.
Ansible Galaxy is the marketplace of Ansible Collections and Ansible Roles. However, only those frequently downloaded scripts are useful in general. Others are just for a niche use cases.
Finally, the Ansible comes with Ubuntu 18.04 APT repo are outdated(Version 2.5), you need version 2.8 or 2.9 to be useful. You can install by installing the via installing the Ansible APT library.
sudo apt update
sudo apt install software-properties-common
sudo apt-add-repository --yes --update ppa:ansible/ansible
sudo apt install ansible