There is a huge learning curve. It takes time to get to know your child’s intricacies through the lens of ADHD and see that what looks like laziness and defiance is lagging skills and dysregulation. He’s very young and it’s really tough before around age 9, when they start to develop some self-awareness.
I would start working with him on his emotions — communicating them more appropriately and regulating. I like using the Zones of Regulation for this. It can really help with his anger (anger probably only looks one way to him, but there are many variations of angry and many ways to express and cope with that feeling).
There are so many aspects to ADHD that aren’t addressed in the diagnostic criteria but are affecting your child greatly:
ADDitude Community Moderator, Parenting ADHD Coach & Author, Mom to teen w/ ADHD, LDs, and autism