How to fix a malfunctioning air conditioning system in an Audi A2?

My Audi A2's air conditioning is not functioning properly. When I turn it on, cold air does not come out and it makes strange noises. How do I troubleshoot and resolve this issue?

First, check the fuse for the air conditioning system. It may have blown and needs to be replaced. If that doesn't solve the issue, the problem could be a faulty compressor or evaporator. It's best to take it to a certified mechanic for a proper diagnosis.