Of course, managers are not elected and, if you are assigned to them, the employees under your authority are obliged to follow your instructions. But the effectiveness of the work of the entrusted unit largely depends on how much you will be an authority for them, on your relationship.
Be sure, after you are introduced to your employees by the management of the enterprise or the head of the personnel department, hold a general meeting with the team. Briefly tell us about yourself and your work experience. In addition, it is necessary to immediately express those requirements, the fulfillment of which must be mandatory, this, mainly, concerns issues of discipline and responsibility. The fact that everyone in their workplace must work conscientiously is self-evident and non-negotiable.
At first, you should not make sharp castlings and changes. Look around and look into the matter. Ask your deputy for help, do not hesitate to ask clarifying questions to your employees. There is nothing wrong with the fact that some of the nuances are not known to you. The desire to understand the essence of the matter will not affect your authority in any way, but it can strengthen it.
If there are experienced professionals among your subordinates, you should not try to compensate for the lack of your experience and professional knowledge with a rigid, authoritarian demeanor. Make them your allies, not enemies. Of course, it is more pleasant to communicate with flatterers and sycophants, but do not replace them with quarrelsome specialists who have their own opinion. In the event that you want to really establish effective work, and not a comfortable existence for yourself, respect them and, when making decisions, ask them to speak out. This is especially necessary at first, so as not to break the wood.
Learn, delve into all the subtleties of the department's work, study not only the technologies, but also the team, the connections that have already developed and exist in it. You can, then, choose as the most effective, authoritarian method of leadership, but this should happen no earlier than you are confident in your strength and knowledge. To use it at first, not knowing all the subtleties, is simply stupid. You will be laughed at behind your back, and you are unlikely to succeed if subordinates do not believe in your competence.
By asking strictly, demanding strict adherence to labor discipline, you, nevertheless, should not be for your employees only a commander who is not interested in people's problems. Make it so that you can be asked for help, make indulgences in cases where it is necessary. Talk to each employee separately, tell them that you are counting on their experience and knowledge. This will make them want to work, and they will try not to let you down.