How can I start?

Hi all,
I'm just starting to learn OpenTofu for my master's thesis.
My objective is disaster recovery (DR) testing: I aim to build a practical framework for testing the DR capabilities of a Kubernetes cluster.

I plan to implement the entire infrastructure using the following tools:

• OpenTofu: to provision virtual machines, configure networking, and perform updates, using VirtualBox as the provider.
• Ansible: to configure the Kubernetes cluster (installing Kubernetes, kubectl, joining nodes, etc.).

The Ansible configuration is already prepared, so now I need to set up OpenTofu.

How can I get started with learning OpenTofu? The documentation seems quite difficult to follow.

Thanks in advance!