Yes, there are many gradual paths to learning Unity. I would highly recommend following the official introductory tutorial series. This covers core topics like Components, Transforms, Prefabs, Game Loop etc. After this it gets a bit less clear how to proceed. If you're already a competent programmer I'd go straight to just prototyping ideas and reading the documentation in depth. I would especially recommend reading the best practices guide.

Regarding the development environment, yes it's very integrated and isolated. For me this was a bit of a culture shock as I generally prefer working with text rather than IDEs, but I've gotten fairly well acclimatised to it now.