Where do we go from here

"But I'd like to know what we are going to do from here. What can I be doing differently so I don't mess up any more than already have, trying to hold him to neurotypical standards that he can't meet?? Where is the line between what is a reasonable expectation and what is an unreasonable expectation?"

You are asking the right questions. Your son is fortunate to have a parent like you who cares.

You can read up on autism or look for material from individual people that describe what their autism is like. However, don't get caught up in stereotypes. Every single person is different. A popular phrase is "If you've met one autistic person, you've met one autistic person."

There are some general trends and traits that you can look for and work with, such as the social difficulties that are common with autism. For me, learning all the rules for getting about in society was a self-led study in painful mistakes. You can help your son learn by explaining the rules of society. Many NT's (NeuroTypical or "normal" people) learn these rules naturally and often without consciously thinking about them. Autistic people often have to figure them out on their own. (Danger! In this paragraph, I started generalizing about autism, which means I'm going to be wrong about many autistic people).

That social example aside, your son will have his own unique gifts and challenges. You will have to learn what those are and how to help him learn to use his gifts to overcome the challenges. Develop a growth mindset and help your son to do so, too. Autism is not all limitations and liabilities. It requires some trial and error to figure out what works. You are basically writing an owner's manual for someone who didn't come with one and for whom the standard owner's manual doesn't work.