I´m not sure if there is anyone in our communtiy yet from Mönchengladbach, but there is a Facebook group that posts events in Mönchengladbach where you could meet people!
I don´t see any events coming up that are hosted by the organization, but there is this event:
I would visit their office and see if there are discounted tickets to the event, and ask for other advice about making friends in Mönchengladbach!
Address: Waisenhauststr. 22
All the best :)