teenage son newly diagnosed

Hi

My son is aged 13, and has been diagnosed last week on the ASD spec.

He also has ADHD and ODD and lots of Anxiety, I am coming to terms with the diagnosis although I had a feeling, it hits you when it is actually confirmed.

Not sure what i do now?

He is attending alternative provision and we are trying to find him a special School. With him being 13 I have to find new ways to parent and not sure where to start, he also has PDA and is very reluctant to do new things or go out with me it can be a nightmare!