The touring plan isn’t meant to account for nor include the participation part of Jedi Training- only the viewing part with showing up with enough time to find a place & watch the show. However, your hunch is correct, you’ll need to sign the kids up for participation. To reflect that in the plan,manually add a break for about 10-20 min (although I have never had it take more than 10 min to sign up, I’d plan for just a bit of cushion just in case).
Sign-ups are located at the exit of the Star Wars Launch Bay. If you’re heading towards the entrance of Autopia, it’s up a ramp to the right (if you’ve been to Disneyland in the past when Autopia had a FastPass, it’s where the FastPass machines used to be). There’ll be a sign directing you up the ramp so it won’t be hard to find.
They’ll start sign-ups at the start of MM but the usual practice at Disneyland (always subject to change though) is that they will only allow up to 50% of each show to get booked during the extra hour. Once reg park opening at 8am happens, they will allow the rest of the spots to fill. I usually recommend heading to the sign-ups 5-10 min to be there just ahead of the regular park opening crowd, but to still maximize the use of your extra hour for MM riding rides.
At sign-up the kids will have to be with you to answer a few questions (like can they follow directions, are they ok being on stage, etc.), then you’ll get to pick a showtime & they will give you a paper with a return time on it (~30 min before the show) that will be the ticket for them to participate.
As for time of show, I’d do one a little later than 10:30, since you’d have to be back by 10am to get them setup & that time is still good time to ride before lines & crowds build. But it also depends on what other shows, meals or breaks you’re considering for the day.