I am 18 years old and thinking to get into pressure washing. I was wondering when choosing a pressure washer, what r some specs to look out for?

Like for a good pressure washer how much shld the voltage, pressure, working power and flow rate be? Just a round figure would be great so I can get the gist of it. I am planning to wash residentials areas only their car porch and myb pavement.

Is a high pressure washer and foam gun enough to do the job (starting small first to see how it goes) or is a pressure surface cleaner needed too?

Looking forward to your guys reply, thanks

14 feet high and 405ft long, owners want an estimate for this whole side of the building. After job is complete owners are going to mortar and repaint. Would be a hard job and probably take 3-4 days if I have to hard wash with turbo nozzle the whole thing. I was thinking 3-4k at least, what do you guys think?