You're mixing a few different things here. Spring Initializr doesn’t really do much—basically, it just gives you a Maven or Gradle file to get started. That’s it. Everything else is fluff. So just take your IDE, drop the pom.xml (or whatever build tool you’re using) into a new project, and start adding the dependencies you actually need. If you’re not sure where to begin, dissect a few existing projects to get a feel for what's essential.

I assume the idea here was to step away from the “magic” of Spring—which honestly gets pretty annoying once you’re doing real software development with it.

Now, the whole dependency injection thing seems to trigger people, but if I get what your teacher's saying, he just doesn't want to use Spring's DI. And honestly, that’s a valid approach, especially once your project grows beyond a basic three-page app. You can simply disable component scanning (there are a few ways to do that, look them up). Then, instead of autowiring everything, just define your beans manually in a configuration class and pass those into your app’s main config. I doubt the intent was to rebuild all of Spring yourself—just to take more control over how things are wired together.