Weighted Overlay Example ArcGIS Pro 

He never uses the actual weighted overlay tool in this video.

Is it okay if my weight values are in centesimal form, like 0.03?

thanks, but how you got the waights ? 0.3, 02. .etc please?

When I input my slope raster in raster calculator with the same parameters I get an error: AttributeError: 'str' object has no attribute 'minimum'. Any reasons why?

You're missing the actual Weighted Overlay task which should come next