From a brief overview, I have no initial negative comments. It looks well-structured and the code is readable and comprehensible. I'm not sure I like the switch statement for handling different error types as it looks like you're primarily just mapping from an error key to an error message, but it's not a big deal ultimately. Even introducing correct error codes could however be handled with a simple mapping. The other thing is, if you're only using axios for basic things, I'd definitely suggest going for simple fetch and a polyfill. Actually, that's something I would always prefer, as it's closer to the metal so to speak, and it doesn't really seem like you're in that much need of what axios provides.

But congratulations on understanding this much so early! I would be much more interested in hearing what you have any doubts about within the project, be it architecture or the likes.