DaVinci Resolve is awesome, but you're right that Spanish-language tutorials sometimes move too fast or are pretty surface-level.
I'd recommend looking for YouTube channels in Spanish that focus specifically on video editing - some local creators explain things step by step and with more patience than the English-speaking guys.
Plus, the Spanish Reddit community has threads where people share resources and help with specific questions, so don't be shy about asking there if something's still not clicking for you.
Another option is to start with the absolute basics in any language, just to get a feel for the interface, and then the more advanced tutorials will make a lot more sense even if they're fast-paced.