That would be pretty hard to do! Children with autism come with a variety of personalities, abilities, interests, etc.
The most obvious thing you'll notice is the lack of social skills, most likely. It will take some time for you to learn to communicate and understand the person you are caring for and get to know them well. You will get to understand what they like, how they prefer to communicate, etc as time goes by.
Other things you'll tackle might be other impairments that sometimes come along with autism, such as down's, cerebral palsy, retardation, etc. But not all children or adults with autism have these other conditions.