Try to act in the most natural way possible (don´t take this post and get reading it, so they will notice that you are puzzled with the matter of what to do).
Be confident, you really have studied some more than those students, didn´t you? Mistakes? Everyones makes mistakes, teachers included...if you don´t know a word, expression or something, you can say that you will take notice and in the next class you bring something that clarifies his/her doubt.
Just don´t get anxious, or hurry up to say something that you are not sure of; but if you do, and someone points out that it´s otherwise that´s okay, give him/her credit in a friendly way. We can be tired, mix up things or not know everything and all the time.
Sometimes there are exercises that can be done in pairs, others the whole class can interact, and so on. This way you get to know your students, conversely they get to know you and one another.
Some more advice (you don´t need all that, you sieve from it what you need):https://teaching.usask.ca/articles/effe ... cation.php