When someone gets a promotion or starts a new job it is necessary to bridge the gap between his old job and his new job. You will feel overwhelmed at first but do not let that affect your performance at work.
When you are new in your role, you have to anticipate challenges. The first few weeks of any new job are always difficult, and even seasoned professionals admit starting over is tough. Get a mentor, this is an excellent way of learning from experience peers. This will also help with your professional working relationship.
Be prepared to adjust because a new job means a may mean new environment, new colleagues, new tasks, and so on. In order to be able to perform the new job well, adjustment is key. Bring the lessons you learn from the old job and embrace the new lessons of the new job. Do not be afraid to learn.
Most of all, do not forget to have fun. Remember you took the new opportunity because you wanted a change. Embrace your new job and take note of the lessons learned from your old job.