Good time to start. Don't see why you need a hotbox whilst starting out. You'll be buying petrol, kerosene and diesel for this kit if you plan to run a petrol washer with a hotbox as well as a generator to run the burner fan and pump. Stick to cold and domestic work and work up slowly. Get a load of leaflets made up.
I started out with a petrol washer and moved onto diesels. 3-4 quid a day on cherry.
But I suppose it depends what money you've got to throw into it.