The first is simply a question about what an embedded interface is. Any way in which you learned about this feature should also answer the question.

The second isn't related to Go.

The third I can see as being a bit confusing, but isn't it something you try once and then remember forever?

Here's one: Creating a new variable via shorthand that shadows a variable in an outer scope - that can be confusing and an easy mistake to make.

But broadly, I would strongly advocate that it is simpler than most other languages, even if it has some quirks. In the same vein of "If I had more time, I'd write a shorter letter", sometimes it takes a bit of time to understand why something is simpler than the alternatives. No language has zero ramp-up. Go doesn't exist in a vacuum, you have to compare it's learning curve and complexity to other languages.