I think it’s good that you want to work to earn money, so congratulations on your initiative. But today is July 15. Most people have set up their lawn services back in March, so I’m afraid you may not find many customers. Yes, it is a good idea to charge by the size of the yard, but do you know the going rates in your area? To give you an idea of rates, I pay $50 a week for an acre yard. If I lived somewhere else, it would probably cost $200 a week. So you will have to know rates in your area. Good luck!