Take food and drink; more than you think you will need. Be prepared for a lot of waiting, sitting, stretching, warming up, stretching again, warming up again. For example, I arrived at my first tourney at 9:30AM, and because I was only doing no-gi, my first match was not until3:00 PM. I only took a single meal replacement bar. At 3:00 I was hungry, drained, and ready to leave. I was fatigued before my match started.