This will be a very short tutorial.
To create your first mod, go to Eclipse, and click on File -> New… -> Java Project.
Add a name to your project, and then click next. You don’t need to set other settings. After clicking next, new UI will appear. Click on Projects tab up top, select Add…, and add the forge project to your mod dependency.
Now, delete the “src” source folder. You won’t need this, instead add another two: “src/main/java” and “src/main/resources”. The java source folder will be your code location, while the resources folder will be your assets location.
If you want to try and run Minecraft, click on the small black arrow beside the Run button, on the top toolbar, and select “Run Configurations…”. A window will appear, here create a new Configuration, in the Project box put in the project name, and in the Main Class box, put in “GradleStart”. You can now click on run and Minecraft will run!
That’s it, click finish, and you’re done! You can jump to actual coding!