Let your DJ know what type of party and guest list have and what you are trying to accomplish and let him/her make some suggestions.
Do you want people to get up and dance or are you just trying to set a mood?
Is it a dinner with dancing afterward or a party with people coming and going throughout?
Will there be speeches, toasts, etc.?
Afternoon, evening, or late into the night?
Is yours a "party" crowd? (Don't go strictly by age - my 75+ yo mother has been one of the last to leave on more than one occasion.)
What kind of music do you and your friend listen to/dance to?
Be sure to include some of your all time all time faves (the highlight of my cousin's graduation was listening to a few of the songs/artists she thought was "sooo coool" as a youngster) and most important:
Don't overthink this - relax and have a great time!
CONGRATULATIONS!! You are graduating COLLEGE!!