Great that you want to help us to build a Scratch Wiki in your language! There is already a small community of your language, see: Spa:Test_Scratch_Wiki_Home. Best places to start is the International-Scratch-Wiki-FAQ that tries to answer any question that could come up. For example read:
- S:FAQ#What should be my "first steps" after my account is created?
- S:FAQ#Where do I find a basic introduction for editing the wiki?
- S:FAQ#How do I start a new scratch-wiki if there is no one for my languages ?
- S:FAQ#Could somebody help me?
- S:FAQ#How can I see what's going on on the wiki?
Your question about [[User:Sandbox]]
At https://scratch.mit.edu/users/JavierR100/#comments-23701224 you asked: "t's possible to move "Mistaken" posts (example: User:Sandbox) to the userpage?". I'm not sure what you exactly ask for, but your edit at User:Sandbox was moved here as you can see here. So you still can copy&paste it where ever you want