ADHD in children

Does anyone have a 3 year old that has been diagnosed with ADHD? I’m taking my son to a child psychologist next week to see about it because I 100% know he has it. His dad also has it. But I’m just wondering what helped you cope with it? Some tools/exercises? Did medication help? any advice would be great. I’m 36 weeks pregnant expecting my 2nd child and I’m honestly really nervous as to how he is going to react and be with the baby.