first of all, congratulations for getting into Delhi University. 😀
I have recently graduated from a girls’ college of DU. believe me first year was the best and during the 2nd and 3rd years i got lazy (really lazy).
You’ll get endless oppurtunities in the form of societies, competitions, internships, etc. I would suggest you to join at least one college society or any student body. it’ll help you socialise in a good way, not just in your own college but on a larger scale.
about adding to your resume, you’ll get to know about a plethora of internships in fields like content writing, social marketing, campus ambassdor,etc. these do not require a great amount of time commitment. it’ll be your job to assess the pros and cons of each and join accordingly. Plus, you can do one full time intership during your each semester end break. Go with the ones that complement your course.
Also, take up activities that require planning, organising, coordinating(fest season helps).
Lastly, do focus on your grades and maintain this enthusiasm till the end. You’ll have a great time! 🙂