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
You can't enable Spring support with IntelliJ community Edition, it only available with paying version (Ultimate).
However, you can create the .xml file manually and CE version also supports it (a little bit).
To working with Spring or J2EE, you should get familiar with build tools like Maven, Gradle (or Ant in some special case). The concept is simple and you can get it easily from the official website (https://maven.apache.org/ - http://gradle.org/).
For Spring, if you don't familiar with creating a .xml file, you can use Java configuration instead or move to use Spring-boot to forget this configuration file (almost).
However, at first, I think you should get the basic concept of Spring and try to work well with .xml files configure. It'll be helpful in the future when you work with it deeply.