Try to have some time each day to practice on your skiing outside the class. A good way to do this is to take lessons in the morning, when you are freshest, and to spend the afternoons going over at your own pace what you have learnt. Ski school is also a good way to meet people, and there may be someone in the class with whom you can practise after lessons. Another good way to improve is to ski with a group of more advanced friends, though be careful of well-meaning but incorrect advice, and make sure that you don't over-stretch your ability.