Pressure Washer (Ashfield CA14)

Power Devil pressure washer. Mains power. Comes with three nozzles. My husband got this from a free site some years ago but I don't think he ever used it. I wouldn't know where to start so if someone can take it that will be great. I don't know how it works and can only assume it does work. It did when he went to collect it but it has sat in my garage for last 6 years at least, unused.