@Pooky1
I totally agree that you should be very careful with a pressure washer! There is a learning curve to using the pressure washer without damaging whatever you're cleaning. I urge you to experiment on several much smaller jobs starting out.
A high level of pressure will damage the surface of whatever you are trying to clean; car, siding, concrete, etc., so I urge you to start with very simple cleaning jobs in order to avoid damaged items.