My suggestion for new cross racers is to pick a good all around set of tires for typical local conditions on the conservative side meaning wider with more tread than a more experienced crosser might choose for the same conditions. Then learn to experiment with the pressure with the same tires for different courses- the right pressure for a given tire casing under different conditions is at least as important to be familiar with, if not more, than the tread pattern. Cat 4/C races aren't won because of tire choice although they can be lost due to spills and other handling errors. It's more important for a beginner to develop confidence at speed, so a "sticky" tire choice with more aggressive tread, lower pressure (up to the point of risking pinchflats or folding) is a better choice than a faster, less aggressive tire while a new rider is on the steep part of the learning curve. And using one tire for most conditions develops familiarity with riding the limits at different pressures- lots of choices for tires but pick one or two to start. And the sooner you switch to tubulars, the better as you have to re-learn all over again!