Young people in Bonn

Ciao!
I'm Italian and I've been living in Bonn for one month. I would like to meet new/international people, who I could go out with on the weekends. But I was wondering...where do young people go on Fridays/Saturdays nights? Can anyone suggest any good places, pubs? I was out last Saturday night but the main square was empty and this made me a little surprised!

I hope someone reads my post and helps me! :)
Thank you
Giovanna