Advice on USA holiday needed!?

Hi, so next year I'm planning to go on holiday to America with my Mum. Ideally we want to see as much of America as we can in around 14 days. The idea of New York to LA sounds great, but need advice on the best way to go about it. We're not interested in doing our own road trip and hiring a car, so is there any good tours or organised holidays we could do? Any advice would be fab!