[Stl files are invalid]

I don’t have the files with me right now but I got them from shape ways and thingy verse they stl.zip files I am a noob at this so I don’t know if that means it won’t work. But one of the files of thing verse was stl.zip but I managed to get it to work I don’t know how.

[Stl files are invalid]

I was trying to put files into cura but every time I put a file in it just says the file is invalid. Does anyone know how to fix this issue. I have tried using different version but it the same.