Seems like you have not set the JAVA_HOME and Not selected JDK Path in eclipse.
First step, set the java home. Follow this URL: https://confluence.atlassian.com/conf59/setting-the-java_home-variable-in-windows-792499849.html
Second step, set the Jdk path in eclipse. By default eclipse takes jre from environment variable.
Look at this post, to setup eclipse with JDK: https://www.gamefromscratch.com/post/2011/11/15/Telling-Eclipse-to-use-the-JDK-instead-of-JRE.aspx
https://www.youtube.com/watch?v=S5xeXawYgK0
Once, you are done with these steps, close all terminals and close eclipse. Start the eclipse again and try performing the steps documented here: https://docs.alfresco.com/5.2/tasks/sdk-develop-eclipse.html
I think you need to jump to Step 9 directly since you have already generated the project and imported in eclipse.
~Abhinav
(ACSCE, AWS SAA, Azure Admin)
