As a Scrum Master you will:
Accomplish your goals by organizing the sprint planning, reviews, retrospectives and requirements workshops
Support, train and moderate your team to ensure a high quality and a high-performance output by leading by example.
Work with the Product Owner to ensure a common understanding regarding targets, vision and user stories
Communicate with all the stakeholders and assure their alignment.
Besides that and as part of the team they will also count on you to build a trusting and safe environment where problems can be discussed without fear of blame, retribution, or being judged, with an emphasis and healing and problem-solving.