What materials for Backend Java would you recommend?

Question

Java

Good day to all!
I want to try myself in backend development, but I don’t understand at all what to build on. I found a playlist of lectures from TechnoPark (by MailGroup) on Youtube, but there are just lectures - you can’t peep the code anywhere. So I decided to consult with you, maybe tell me a book, a resource, or at least a to-Do list of "steps" on which you need to find information.
I just ended up running the server in Intellij IDEA. What further and in what direction to dig - I have no idea.
I would really appreciate any guidance.
Thank you!

Answer 1

in the context of web - WEB - a Java application. What technology stack is needed for a jun?