My son just got his diagnose today

My 4 years old son just received his diagnose today, after more than two years of waiting: Autism Spectrum, level 3. I knew all along he was Autistic, but it still hurts when you have it confirmed. We got the diagnose, but what is it next? I was expecting a referral to SALT or to an ABA therapy. What do you do next? How do you get early intervention? The nursery is slowing working ( since last November) on his EHCP. Will this plan help to get his therapies? I don't really understand how the process of helping an autistic child works. I thought the diagnose will open the doors to the obvious support he needs, but it seems I am wrong. What do I do?