Lone Star College uses Akademos, an online textbook vendor. There are no on-campus, in-person bookstores at this time, though you may arrange to have your books delivered to campus for you to pick up if you'd like. The campus store (selling school supplies, tshirts, etc) is in CB.226.
STAR Bundle update:
Most materials provided through the STAR Bundle will be digital, but not all! If you have physical materials to pick up, you'll head to CB.230.