Answer 1There are three different types of neutrinos. Each one is associated with its own antiparticle, but is not an antiparticle itself.
Answer 2Particle and antiparticle are distinguished by their charges. The positron, for example, the antiparticle of the negatively charged electron, is positively charged. The neutrino, on the other hand, is electrically neutral-the prerequisite for the ability of being its own antiparticle. However, I assume that the antiparticles of neutrinos are neutrinos with opposite spinning direction.