What should I wear while debating?
This answer in itself is not so simple because there is no dress code as such for debating. It all depends on which platform the debate is being held on.
If the debate is from a school, challengers will have to wear the school uniform or as per the school specifications.
If the debate is being held otherwise either the dress code would be as per rules laid down specifically or else the debater can wear something crisp and formal that gives an air of professionalism.
Whatever the case may be determines the dress to be worn for debating but if left personally on the debater, you should wear something comfortable, smart and formal or something that helps you to put forth your topic emphatically.