I have a coming 2 year old that I am planning to jump and/or event in the future, and I want him to have a solid dressage base before I start anything that is not on the flat. I know that I want him to be supple and responsive and do all the things a good beginning dressage horse will do. Now, the problem:

I have no idea what Im doing. I have never ridden dressage before. I rode a former eventer for a short time and that is the extent of my experience. I did barrels before this. I dont want to put 'green on green' with his dressage work, but at the same time, I have to learn too!
I would like to enter him in some dressage tests for fun while Im training to see how he does.

So, do I take lessons on a schoolmaster and then try to teach my gelding, or do I get him training and then try to learn on him????? arg.
ANY help would be welcome. Thanks in advance!!!