As a private hire vehicle, I’d imagine you would do lots of short journeys, so would at least do an oil change every 6000 or so.
As I’ve no driveway, I use the jet wash at my local shell garage. Pre wash then use the foam brush, I keep the brush a few inches away from the car and foam it up. Leave for a couple of mins then reform it and wash with my microfibre mitt. Rinse and towel dry. As for wax, I use Autoglym hd wax once a month, and de-tar and clay once every 2 months.
Autoglym leather cleaner and conditioner once a month.