Not giving the new job enough time
I moved from a small, cosy, coasting secondary school to a big, confident place with a human dynamo head and highly capable staff.
I had been promoted but it felt like the opposite. I was a fish out of water. Time and again I contemplated walking out and going home to my family. Teach long enough and you will meet people, including headteachers, who have done exactly that.
I stuck it out, though, and five years on I was chair of the staffroom committee, conductor of the staff-student choir, supported through an Open University degree by my colleagues and generally enjoying what I still see as the best time of my whole career.
What's the right thing to do?
Each school is a closed environment with its own culture. Entering it will always bring some awkwardness, uncertainty and doubt.
Do not stress about it. Be yourself, engage with everyone, do not listen to gossip and above all buckle down and do the job they have given you, and all will be well.