Bring something to the conversation
The room matches you on interest tags for a reason - those tags are the shortest path past small talk. If you tagged music, your first line can be about the last album you could not stop playing. If you tagged language exchange, say which language you are practising and how badly it is going. Specific beats open-ended every time.
The other person is in the same position as you. Almost nobody in a random chat room is annoyed that you started talking.