Models are flocking to instagram to get scouted, and there is a reason why. Before you post any photos however, you should define your style. Remember, people (and hopefully modeling agencies) will look at your entire profile and not just the pictures.
Consider what kind of vibe you want to convey with your pictures. Do you want to be a high-fashion model, a lifestyle model, or something in-between? These are all questions you should answer before starting your modeling career on Instagram.