Being a Scrum Master in a company is much more than just attending a 2-day training to get certified. Whilst your role is to primarily coach the team, it is also to teach, give advice, be a mentor and role model of the Agile and Scrum values and principles. This is not always an easy task. The knowledge and skills you need as a Scrum Master will grow through education, perhaps some additional coaching and most of all the experience and support of other Scrum Masters in your organization and network.
I love the way Claudette Moore sums up what a self-organised team is all about: Self Organised is the capacity you have as a team