Looks good, but some suggestions to make it better
Issue 0: The avatar (me) image is not loaded. I think this is becasue blocked stream from the target URL. This is simple to block resource by server, when the request origin is not the same as domain expected.
Solution for 0: Always host the resources by your own(this is okay for test and learning right now as you did tho)
Issue 1: You loaded the images as div background images, rather than simple/raw image tag. Using img tags are recommended when you like to just show some image.
Issue 2: Spaces! please add some spaces between elements, and screen edges. Some margin could make it really good.
Issue 3: try not to use absolute units when possible! pixel(px) is a absolute unit, you may work more with relative units like em or % as you did for .column css rule.
Issue 4: Top fixed navigation bar could have some background. Since it’s transparent, when you screel, and if something under the navigation has no contrast with navigation content, so it will be hard to read. A border at the bottom looks good too, something like following