You already have abs! Karate can help bring them to the surface as a frequent core workout will melt away the fat. As part of regiment of diet, core training, cardio, warming up, cooling down, bag work and sparring, Karate can indeed give you abs.
You can spar with training gloves. Both sparring gloves and training gloves protect your opponent but training gloves also give more protection to your hands. This means that sparring in training gloves provides less real-world training than sparring in sparring gloves, which are meant to mimic real fights as closely as possible.
It is fair to say that unless you want to be a professional martial artist who competes at an international level, you are never too late or too old to learn martial arts. You can be too old to become a professional but if you want to do martial arts for fun, weight loss, exercise, or self-defense, age does not matter.