Most advice about parenting an Autistic child is written for the parent’s anxiety, not the child’s life. The advice tends to be procedural. What to do when they melt down. How to get them to eat. How to handle school refusal. The advice tends to miss the question underneath all of those questions, which is whether the parent actually believes what the child is telling them about their own experience.
First, believe them
Start there. Believe them.
If they say the sock is hurting, the sock is hurting. If they say the noise is too much, the noise is too much. If they say the food is inedible, the food is inedible. If they say the teacher is being unfair, investigate. If they say they do not want to hug the relative, do not make them hug the relative. The child has been telling you, in the only language available to them, where the edges are. The parenting task is not to override the edges. It is to work with them.
Second, do not outsource the parenting to a behaviourist. There is a large industry that will, for a fee, try to train your Autistic child to look less Autistic. Some of it is called therapy. Much of it produces adults who cannot tell you what they want or need because they spent their childhood being rewarded for masking. The evidence on outcomes is, at best, ambiguous. The evidence on cost, from Autistic adults who went through it, is clear. Do your reading from Autistic sources before you commit.
Do not outsource the parenting
Third, your child is not a problem with a solution. Your child is a person. The goal of parenting is not a less Autistic child. The goal is a child who knows they are loved as they are, who has the support they need, who is building the tools to advocate for themselves, who can tell you the truth because the truth has never been punished.
Fourth, find other Autistic adults. Not only Autism professionals. Autistic adults. They are the best single source of information about what your child may become, what they may need, and what the common parenting mistakes look like in retrospect.
Find other Autistic adults
The world will pressure you to make your child quieter, smaller, more palatable. The pressure will come from relatives, teachers, doctors, strangers in supermarkets. Your job is to absorb that pressure so your child does not have to. That is most of it. The rest is detail.