Hi Rick, I moved your thread out of the Welcome section (and welcome!), into the Schutzhund training section so people with actual experience can help.
I agree with Lee's suggestion - forget what you have not done in the past - focus on what you can do now to get things under control. Find other people to work with, and proof proof proof focus under all situations and distractions. At this stage, he should have enough of a base in obedience, that you can start corrections for proofing.
I don't think it matters if RoJo is reactive because of lack of socialization or some other reason - what matters is putting on-going, intense obedience work to teach self-control. I started SchH with my shelter rescue when she was 2 years old. I think she was a tied dog for the first year of her life, and reactive to other dogs. May have been lack of socialization, or just how her brain was wired, but she would focus intensely on other dogs, and be off to challenge them in a split second (and turn and growl/bark at me if I restrained her by leash, her frustration at not being able to engage the other dogs spilling over and being redirected towards me).
What fixed it is intense work with a friend and a non-reactive, reliable dog. Lots and lots and lots of obedience work on leash in a group. I went to classes two/three times a week in the winter, meeting with our club and my training partners two/three times a week outside on the field during the summer.
Don't kid yourself. It was work. Lots of work. For both of us. But it payed off. There is no 'trick' of building fun, reward-based obedience in a dog that is reactive and wants to go after other dogs. It is a matter of instilling rock-solid obedience through proofing.
Here is a picture of Keeta (second from left) working on a group long down with my training club from a couple of years ago. I went from thinking that I could NEVER trust her off leash to doing group 30 minute long downs amid distractions. People walking around, balls being bounced, tugs being thrown, people coming to get their dogs and heeling around).
Same thing with the scenario of reporting to the judge - grab your training buddies and practice the reporting in over and over and over and over. Only way to proof it.