Organizing a golang-based project is also something that, while documented, is not front of mind for most new golang users, nor does the "beginning go" posts out there do a good job of how to lay out a project for success.
Code organization: https://go.dev/doc/code
Pretty much everything else you should know: https://go.dev/doc/effective_go
There's one thing I think that people getting started with this language should know and that's in the pursuit of getting the stuff you mentioned right, is making sure the reference material (blog post, book, whatever it is) you're reading is something written within the past two or three years. The official site really has enough that you need to know in order to have good knowledge coverage, but the module system beyond version 1.16 especially is something you need to get right and which a ton of old information is out of date on:
In Go you can at least get pretty far with a totally flat namespace and there's nothing wrong with that, up to at least 50kloc or so. That's less true in any language where files become a unit of modularization.
Not necessary anymore since Python 3.3 (released in 2012).