There are a ton of resources, but unfortunately you'll have to sort of figure out which ones work for you as they all seem to have slightly different approaches and opinions.

Two good places to start (in my opinion), if they don't work for you, just move on:

How to ADHD youtube (aims younger but very positive): https://www.youtube.com/channel/UC-nPM1_kSZf91ZGkcgy_95Q

ADDitude Magazine: https://www.additudemag.com/ (they also have a YouTube channel)

To understand more about it, I really liked reading this book: https://drgabormate.com/book/scattered-minds/

From memory: regular exercise, and emotional regulation tools such as CBT or meditation. Oh, and adequate sleep

https://pubmed.ncbi.nlm.nih.gov/31921425/