43 days out.....does that mean you will be there for Star Wars Weekends? If you aren't really into Star Wars, but would like to do Jedi Training Academy then go during the week and not on the weekend.
I definitely agree with pp's about signing up first thing and needing your child with you to sign up. When we went last year during Star Wars Weekends there were literally people running and pulling their kids so they could get to the sign up and get a spot. Sign-up was at the Indian Jones attraction. During normal times though it is not.
My then 8 year old son and 4 year old daughter did it last year and LOVED it! They teach them little moves and then they get to "fight" Darth Vader. I'm not sure if the character they fight changes or not. At the end they got a certificate.
There is a photopass photographer there taking pictures of the whole thing. They will give you a special photopass card so you don't need to have yours ready. Just make sure you pay attention at the end when they hand out the photopass cards.