To get that book written, you will need to dedicate lots of time to the task.
So when and where? J.K Rowling is said to have written Harry Potter at a café in Edinburgh. I heard Philip Pullman speak at a bookshop (about 11 years ago!), and he said he liked to write in his shed! I remember he said that he would write it by hand, in pencil, and then pass it to his wife to type up.
For me, it’s in peace and quiet on the computer. I usually don’t start until 10pm when the kids are in bed, and all the jobs are done, but for a lot of us, that’s the way it goes.
Work out what kind of environment most suits you.
Make some space in your life for writing!