Remember that as the Storyteller you control the world in which characters play, but you cannot control the players themselves. It is not uncommon for disputes to occur from time to time and typical that players will look to the Storyteller to intervene, defuse or otherwise resolve conflict that occurs around the table. Just keep in mind that everyone is there to have fun and that your focus needs to be on how characters interact, not the players themselves. Your domain is the world in which characters dwell, not their players.
The fun of playing a tabletop game and the key difference between it and writing a story by yourself is that your characters will always do things that you don’t expect them to do. You are their guide through a world you have created but they will not often behave in a way you have planned. You must balance being flexible and accommodating with having to say “no” sometimes.
Try to resolve questions and conflicts quickly to keep the pace of the game flowing along, do not allow players to argue for too long because that can be immersion breaking for everyone.