Where to Start

[rrosson]

If you have a working running opnsense firewall and have this repository what is needed to bring the fresh repository up to speed with you running firewall?

[ansibleguy]

If you are new to Ansible: https://docs.ansible.com/ansible/latest/getting_started/index.html

All of these modules support the check-mode.
That way you can easily test them out without/before making changes: https://docs.ansible.com/ansible/latest/playbook_guide/playbooks_checkmode.html

I would start by picking whatever component of OPNSense takes up the most time when you configure it manually.