Obviously the most important thing to bring with you on the day! Keep it safe.
Most conventions have an e-ticket system, where you can show the tickets on your phone. However, I would always make sure to have a physical copy just in case. The same is true for the opposite way round.
Always have backups! Sometimes the WiFi or signal can be patchy at convention halls, so you may struggle to download it. Or you could lose your ticket on route. Prepare for every eventually!
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