Hi,
While I'm not a lomo-photographer, I've been following lomo for a while. The original, and still most respected lomo camera is the LC-A lomo camera (Lomo Kompakt Automat, built by Lomo PLC of Russia, and available through Lomographic Society International).
Note the term lomo, or lomographic is nowadays used to describe any camera that has the visual effects of a Lomo LC-A. This included camera's like the Holga or Olympus xa family.
As for film, the LC-A takes any 35mm film. Lomo photographers often prefer ISO 100 films, as they produce more vivid colors. Also, you might get even more vivid and surreal results by using expired films or crossprocessing.