Why don’t you look at childcare.co.uk as they have adverts for your area and the prices they charge.
Remember you need all the various insurance, training, inspections and background checks which all need to be kept up to date. You also need to market yourself as you obviously won't make any money with no kids to look after. But with no reputation or reviews you'll find it difficult to get your first kids. It's harder than you might think! If I were you I'd go and work on a nursery or as a childminders assistant first.
I am aware of everything I need. I have 7 years experience working in a nursery, I am fully competent with the EYFS. I have first aid etc
It’ll depend what hours you choose to work and how many children you get signed up… but you have to be confident that you can survive for a while with maybe just the income from one child whilst you build up the business