There are many free via ferrata sites in Spain. I recommend purchasing the essential gear from Decathlon; you can use Decathlon’s affordable alternatives, but try to avoid unknown third-party products. Rappelling and ziplining involve significant risks, so it’s best not to attempt them alone. If you do want to learn on your own, start with the most basic training. Otherwise, there is a high risk to your life—for example, if the distance between the rope grab and the figure-8 descender or the tension of the rope grab is not properly judged, the gear can completely lose its protective function. You also need to learn self-rescue and emergency rescue methods for ziplining and rappelling.