https://playproject.org/
You may want to try this website and a book “ Autism: The Potential Within”. I have learnt so much from this book and took some courses online.

Know that autism is a spectrum with ranges from the highly capable to those have a lot of difficulties. Anything you hear or read may or not apply to your son. Know your son, keep an open mind and see what helps. You may want add your son's age as it is relevant because a kid isn't an adult. The experts usually push for early intervention which is now and don't worry about if you should have acted earlier.

Net work with other parent. Attend resource fairs for information and programs.

Definitely the speech and occupational therapies have helped. I've tried many different supplements, but I was blown away by how much Folinic Acid in particular has helped him. After 2-3 weeks his little eyes opened up so much to eye contact, and he has shown improvement in social skills and speech as well.