I’m going to assume to mean an article on a blog about autism. If so then what you need to do is research about autism and figure out what specifically you want to talk about in the article. Like “how to work with autistic students” or “how to be a good friend to an autistic classmate”. Research about the subject matter and then write about it. Generally in the form of an essay or a list of you thinking about a number of actions you could do.