ADHD and autism

Hi I’m new on this forum and just wanted to introduce myself I have recently been diagnosed with ADHD  and I am awaiting an autism assessment but I know I have got it . It was my first day taking ADHD medication today and it made me feel quite sleepy. i don’t know much about ADHD but i want to learn however the booklet I was given was a bit to difficult for me to understand does anyone know any good websites that I can go on to learn about it that will help me understand it better.