"File" -> "New" -> "Java Project", you should see in the section of "JRE", Eclipse correctly found the "J2SE-1.8", as shown below. Then you input the name of this project, and press "Finish";

Select the newly-created project in the "Package Explorer", and "File" -> "New" -> "Class", input the Class name: "Hello", and make sure you check the box of "public static void main(String[] args)", that will save your time. You will see a Hello.java created in your project.

In the editor, add an output statement to Hello.java like this, and save it.

Then press the "Run" button (a green arrow) on the toolbar, if the result is correctly shown in the console below like this, well done!!!