16 year old, available for childcare through the summer

I am the youngest of two children with one older brother. I am going into sixth form to complete my A-levels in September, but I already have GCSE qualifications, although I am awaiting my second year results which I will get in August. I am available most days for hours between 8am and 6pm and occasionally I can do late evenings. I have had some experience with childcare with younger cousins and volunteering at youth clubs and my local cycling club, where I helped coach and guide children aged between 3-10 years old.