Angela.
AI mode.
A 70-200/300mm lens.
Set for continuous shooting.
Set for shutter priority.
Try to keep one or two players in front of the action (easier said than done).
Spare memory (lots if you've got them).
Spare batteries (as many as you've got).
Polarizer if you've got one and if the suns comes out to play.
Small light weight camera bag.
External flashgun (only if it's really a dull day).
ISO no more than 200 at a push 400.
Shutter speed 1/250, 1/320 depending lens length.
Try to stay somewhere around the half way line, but be ready to run for a line out when they happen. If it's a following game you may need to do some fast walking or running to keep up with the players.
Comfy trainers is a
must.
Above all else
RELAX and
ENJOY yourself, don't beat yourself up if miss something.
That's all I can think of I hope you have a really good time
