The beginning of your book is important - which is a truism! However, the beginning is also very tricky. In a different context I see this problem often with the students I mentor. They are so intent on getting the opening of an assignment as good as possible that they are almost paralysed with terror. Here, I advise them to start on the main body, for instance and worry later about the introduction and that elusive perfect opening paragraph.
Here are what I see as the main problems with the beginning of a book.
1. The temptation of give too much information - desperate as you are to draw your reader into your story.
2. The terror of delivering a clunky or clichéd opening para - ...it was a dark and stormy night...!
3. Wondering exactly where to start. I've often heard that a writer could often happily dispense with opening paras even pages of their book and the end result would be the better for it.
4. The sheer size of the challenge ahead - a bit a day, though and it's amazing how quick that word count grows. But - you have made a start and that's amazing.
5. Thinking about all the other books out there and wondering how you can possibly compete.
Here is some basic advice.
Every single writer sat where you sit now. You can always edit and change and improve - in fact, you must edit and improve. Very soon you will be into your book - that will only happen by making the start. Do it.