This is just like what people do when they want to learn a profession. Being a disciple is like being an apprentice. If you want to be a carpenter, you become an apprentice to someone who is an experienced carpenter. You go next to him and watch him. You copy what he does. He gives you advice and tells you what to do and what not to do. Your goal is that after a few years, you will be just like him and be able to do the same things he does. It is the same way if you want to be a hairdresser or a mechanic or a rice farmer.