Look into using back button focus. I understand the majority of sports shooters use it in conjunction with AF-C, as it allows separate focus and
shutter control. I've started using it for all my photography now.
Re
exposure, it's probably best to use the widest
aperture you can to get your
shutter speed up to 1000th of a second to freeze motion. This should be easy outdoors - you should be fine to shoot at 100
ISO pretty easily in sunlight.
If you've got constant
light you should be easily able to shoot in manual mode - just find your
exposure and go. Otherwise you could look at Av and setting a minimum
shutter speed.
Good luck! I'm hoping to head down to the Open next year to shoot.