As a beginner, you don't need more than one or maybe two of the beginner books. Once you get some experience playing, you can buy more advanced books and pieces, but you don't need all of them. If you do want to pursue the flute seriously, consider expanding your library to include at least the Mozart concerto, Bach sonatas, and French pieces. But don't feel like you have to buy everything now. It's taken me almost a decade to build my flute library, and this isn't even all of it.