I have very good pure Java basic knowledge. As long as there are no XML config and no project management tools involved, I am very good.
The things that really confused
I know you are asking about IntelliJ Idea but as it is a commercial tool, you should pay to let you use its plugins. Another way is using "Spring Tools for Eclipse" which is a great environment to develop Spring applications. But you need to be familiar with eclipse. It can be downloaded from: Spring Tools 4 for Eclipse