This sounds like an exciting new opportunity for you. I understand that you have a lot of questions as this will be your first teaching post. I’ll try to answer your questions in order.
Regarding training, there is a Certificate in Teaching English to Young Learners. You can get information about this from the UCLES website. It is usually a two-week course. However, to be accepted onto the course, you will need a certificate in Tefl.
If you don’t want to do this or don’t have the time, you could read books to learn about teaching. You could look at Teaching English in the Primary Classroom by Susan Halliwell and a book by Brewster, Ellis and Girard about teaching primary – I don’t remember the title of this book. Both of these books will provide you with ideas for teaching and lesson plans. The Halliwell book also has a chapter on expanding activities in the course book.
With the younger children, you should focus on spoken language: you can do songs, stories, rhymes, etc. You can play games with them. You will be able to repeat many of the songs in subsequent lessons. Primary children like to have the opportunity to repeat things they know well. With the six year olds, you can introduce some writing but don’t do too much of this as they will be learning to write in their own language. You can limit writing to copying words or tracing words. Primary children will need a lot of variety in the classroom, you will need to change activity regularly. You can look at some of my other answers about teaching primary for more information.
As for teaching phonics, you could take a look at the book “Phonics Games” by Michelle Ramsey. There are also phonics websites that you could check out. I suggest you write in to me again when you have looked at the course book you’ll be using. If you describe the approach to phonics that is used and outline an activity in the course book, I’ll be able to give you ideas for expanding.
As for childcare, I don’t really know what to say. Do you have a friend, someone you trust, who could look after the children one day a week? You could return the favour on another day.
I am sure you will enjoy the teaching once you start it.