How would I go about reaching out to a company and tell them that I have autism and is there maybe a website or a company that actually prefers autistic people?
Everyone has their quirks and challenges, and IT is ripe with a ton of undiagnosed Autistic people among tons of other mental health challenges. Unless your autism impacts your ability to function at a basic level, there's really no reason to disclose it at the application/interview stage. When you're being screened/interviewed be sure to be clear about the working environment you're looking for and try to be mindful over time of your capacity and be sure you're communicating about your workloads and statuses regularly.
I think data and testing is one of those.
Eg. Here https://auticon.co.uk/now-hiring/
You might want to check out sap https://www.sap.com/about/careers/your-career/autism-at-work...