I haven't looked at your book--but prepare yourself, because those that give feedback try to tell you honestly where the problems are, rather than praising you and telling you how everything is wonderful.
Don't do the give-the-book-away-for-5-days thing if it's your only book. All that happens is that anyone who might have been willing to spend money on it now owns it for free. And while you may get an upward blip in the "free" rankings, your rank among paid books will sink from sight. The two sets of ranks have no effect on each other, and if you have 5 days with only freebies, then anyone who sold a book for money during those 5 days will pull ahead of you in rank.
Welcome to KDP! It's a lot of fun, but selling your book is a lot harder than writing it.
You're up against a lot of competition, thousands and thousands of books, all with captivating covers, intriguing blurbs, scintillating narration and dialogue that is realistic and properly formatted. I think your book (actually, at only 80 pages, I'm reluctant to use that term) needs more work before its truly competitive with all those other books. As to giving away your only book, you only succeed in losing customers.