I'll just second Gabranth's statement, especially if you aren't used to wearing heavier armor or hefting a heavier shield, it will definitely wear you down and tire you out during the event, particularly if you're going to be in a lot of fights. There's a fine line to tread between authenticity, bamfness, and comfort. Ultimately while you do want your costume and armor to look awesome, keep in mind that you're going to be wearing it for long periods of time, while being physically active, getting into fights and running through the woods. Pay attention to your personal comfort while wearing the costume. No one wants to have a bad event and being uncomfortable will just drag you down.
Realms of AdventureLive The Magic!