The best and easiest solution for you would be just uninstall everything
Then install the JDK and JRE
after that install eclipse.
if you do this way. Eclipse Automatically will take the settings and it would be easy for you to work.
Q>How to automatically import files in eclipse?
Answer >> just press ctrl+shift+space in your computer. if all syntax of your code is correct all the required classes and packages will be imported.