If your goal is the migration, then go with the droplet approach since you have no experience with K8.
If your goal is to learn and you have time to delay the migration, than start learning k8 and when you feel confortable enough create a test environment of your setup in k8.
Heads up K8 is awesome, but there is a lot of information to process before you become proeficient, that being said might not be the best solution to use it in production while learning.

I agree with the previous statement, and I would add: Running WordPress in Kubernetes is not trivial (in my opinion), especially if your goal is to leverage all the great automatic failure handling that Kubernetes provides. WordPress is easy to use and runs extremely well on a single server, but distributing it can be challenging.