Getting my son organised for highschool

Hi mums, my eldest will start high school in just over a week, he is currently on a wait list to see a pediatrician as I suspect he might have add. He's got trouble with getting organised and I have to tell him what to do, down to putting jox on, if I don't it won't get done as he gets distracted. He's also had trouble since grade 4 to get tasks finished in school and is easily distracted. I'm just wondering if there's anyone else out there who's got an older child that's not yet diagnosed ( we've been on the wait list for nearly 2 years) and how I that case you help your child getting organised, have you got any good suggestions of getting ready charts for older kids etc? I worry so much that high school will be too much for him and that he'll end up
In trouble because he can't keep up. Thanks in advance for any suggestions.