I'm a latecomer to this discussion, but I do have some experience on the matter.
Remember that when an autistic person goes into meltdown, there is nothing you can do to "fix it". The meltdown does not happen out of ill will, lack of common sense, or any paracetamol one may or may not have taken during conception.
It is a sensory overload, and a protection mode.
What you need to do is to be there, and provide the calm, the understanding, and the protection. Deal with the issues when calm, not while in meltdown. No autistic wants to have meltdown, but neither can they prevent them once the overload kicks in.
You're doing the right thing, because you posting this question shows that you seek information! Educate yourself, through -proper channels- ie. not "antivaxxers united" and anything vetted by RFK Jr, but preferrably by someone with education on the subject.
There are a few good sources on youtube, but be careful, it is a rabbit hole it can be hard to get out of.
@autismfromtheInside and @Auticate have been good for me, and there are others also. But as I said, be weary, the YouTube University can be a tricky place to navigate and remain sane...
And most important of all: Do seek help. Raising an autistic child can be a fulltime job, and it WILL take a toll on the parents. Seek relief and time-outs, to get your batteries charged! If YOU, who shall be the safety and comfort to the child who is melting down also melt down, there will be carnage, and nothing good comes from that. You need your strenghts and powers to do good!
And remember, autism is not a single diagnosis that is equal for all. It is a spectrum, from one end to the other. If you've met one autistic person, you've met just that, one autistic person. Not all of them.
In certain areas, the autistic brain functions way better than the neurotypical brain, and some can indeed call it a superpower. But in order to harness that power, they need to learn to accept and handle their condition in a society rigged for the neurotypical, not the divergent. And that is where you come in, by providing the safety, comfort and security required to be able to do that.