As you might imagine, putting on a Training Level Three Day Event takes a lot of work. If you can't ride this year, and aren't grooming, how about helping out doing some of the essential jobs behind the scenes? T3DEs need stewards, starters, timers, Roads and Tracks gate judges, cross country fence judges, and showjumping ring crew.
You may attend any lecture or clinic for free, and it is a perfect opportunity to learn about competing in a future T3DE.