[English-coach]

My advice, for starting your day is have fun and get to know them. Play games or do activites that allow you to tell them about yourself. If it is children, they will love getting to know you. If they are teenagers you might have to test the waters and see.

Play some icebreakers (games to break the ice) and relax. Have fun and I'm sure you will do fine.

[HUE]

As everyone else has said, don't worry. The students will likely be more nervous than you (although they may not show it).

Something to consider in terms of activities and preparation, always plan for more activities than you'll need. It's easier to remove some games/icebreakers, or even shorten and simplify them, than it is to come up with extra ideas on the spot... especially if you're new and nervous.

Good luck and let us know how it all goes!