Server World Problem

So I'm trying to get a world off the internet and uploading it, and I am getting a "schematic" in the folder, then i try to upload it, and apparently it cant find a world in the folder. I don't know where to look for a world or anything like that. So if you don't know a fast solution to this, I'm fine with being pointed to a site that gives you what you need from the get-go.