Dear Kazi Sagar,
Welcome to the Wefugee Community!
Do I understand you correctly, that you travel to Stuttgart and you need a place to stay for a few nights? Maybe you can register on the Couchsurfing platform in order to find a host. Beside couchsurfing, the next cheapest option would probably be to stay in a hostel dorm and share a room with other people.
I hope this helps and safe travels!
All the best,