Hi Adrian.
Here I can help only with JoomShaper products. We are not Joomla support, nor Joomla Translator Team.
We don't provide translations for templates, this already rests in the hands of webmasters.
Depending on the template you use, you will need to translate selected phrases from this file (or another name associated with your template)
language\en-GB\en-GB.tpl_megainc.ini
of course change prefix , and folder.
Just check which phrases you really need on the front-end, and translate serveral of them. Sometimes it's only 15-20 lines ;]
Remember, that all the components used in the end also require translation.
Spanish Joomla community is still strong, so ask their members maybe they have translations already.