is there a site where I can to learn to play SA-45 for free?

Question

SA-45 is a 32 key musical instrument like a piano

Answer 1

No, I don't think the Casio company has provided a web-site where you can learn it for free. They are in the business of making money, and they want you to buy the book. You can probably get one free from the company at this address:

Casio Customer Help Center
570 Mount Pleasant Ave
Dover, NJ 07801

or this phone number:
609-395-0154