Gaurav,
How interesting! What are the parameters and/or goals of the internship? Does the intern have any current marketing automation skills? That can all help to set the stage in terms of projects.
So, depending on all that, you might consider diving right into execution, starting by creating "day in the life" scenarios to drive coaching sessions and then ask them to support the scenarios in Eloqua depending on how quickly they learn. Say, perhaps, starting with building campaigns, then drilling into specific assets, then - depending on your confidence level in the intern - including segmentation and execution. You could balance that execution with various administration, integration and database management tasks/projects - not the most "amazing" work, but standardizing foldering structures and naming, updating integration mapping documents, digging into email deliverability reporting details - all these tasks provide value to both you and the intern.
For something different, you could select several value-add, but lower LoE, apps from the Appcloud to have the intern support the build-out and launch to test. Everyone likes to build stuff.
One thing we did with our last few interns at HQ was to have them schedule 1:1 meetings with various folks across our marketing teams to gain a better understanding of a wider range of roles and responsibilities as well as ask for any "getting started" advice. It was very well-received.
Best,
Kristin