What pied said.
Also, most band music, you'll maybe see one song with that low B. I've heard that modern pieces do make more use of it, but the composers also are aware that not everyone has the low B, plus it's typically at least intermediate-level players that can consistently hit it.
So chances are you'll never see a song with that low B for many years. And if you do, you can either skip it or usually play D instead.
Enjoy your "new" flute. And find a teacher before you develop bad habits. Even a good high school flutist can get you started right.
Flutes:1975 Gemeinhardt M2 in chrome nickel;1982 Armstrong 80;2006 Yamaha 584
Piccs:1978 Artley piece of crap 15 P;1982 Gemeinhardt 4S;1980s? Armstrong all wood (no model)
Bass:2006 Jupiter di Medici G0199
Treble:2009 Guo New Voice
+ many flute-cousins