What kind of positions are they in rugby?

It depends on your size, shape and weight. A tall person would make a good second row. A short, thickset, strong person would make a good hooker. The smallest player on the pitch is generally the scrum-half. And the fattest would be the prop. The fastest would be the wingers. The best kicker on the team would be the fly-half. So the best position in Rugby depends on your body shape and skill.