Junit or TestNG for Fresher in Automation Testing

Hi,
I have gone through Junit module and as suggested to have knowledge ONE framework, i have skipped the TestNG module. But while going through examples/scenarios in Module 17, i observed that you have used TestNG always and looks more user friendly than JUnit.

I am New to both the frameworks and know Core Java. I have enough time to go through the TestNG module.
Do you suggest to use Junit or TestNG? I want to make myself sure before going into the Frameworks from Module 18.