So, you're an Ohio boy, Uxley. I thought that I sensed there an underlying intelligence and respectability to your posts!
What part of the state are you from? I'm an OHSAA umpire in the central district. Our local association has around 400 members.
Our certification process sounds about the same as what you are going through. My understanding is that the process will vary from region-to-region within the state.
For those in the Columbus area, there are the same weekly classes. Those are followed by an open-book test that must be passed with a minimum grade to become certified. Pass, and you will then be a "class 2" baseball official. This will qualify you to work JV and middle school ball.
To move up to the varsity level you need to take another round of classes the next year. That is followed by another mandatory test, this time closed-book. Make the grade there and your permit will be bumped up to "class 1" status.
You can get the permit without being evaluated on the field, but before you are assigned to any varsity games you will need to be field evaluted by senior members of the local association.
To remain a member in good standing, you need to attend a set number of rules and mechanics classes each and every year, as well as the mandatory annual state rules interpretation meeting.
Our local association also hosts an annual field mechanics clinic every March.
That's the way we handle it here. You might have to do something different in your area. But stick with it, one step at a time. Attend the classes and take the tests. Take advantage of every bit of training that your association offers. And look beyond that to get all of the training and experience you can find to better yourself!
Good luck!