Create a schedule, to help students get in to the everyday workings of a class. Outline the times each subject is taught. Plan out how you will teach each subject to the class and for how long each subject will be required to be covered.
Teach the students what behavior will be tolerated in the classroom. Have a signal that the students will follow to let them know when they are being too loud, such as putting up a hand in a stop signal way, to let them know to quiet down. There can also be a different signal, like a hand clap, to let the students know that their attention is needed.
Have a routine mapped out for the students to follow each morning when they arrive. Instruct them on where their backpacks and coats go. If a student is early, have an established routine until the other students arrive, such as reading quietly in the class. If the students show up early and are playing on the playground, they must form a straight and orderly line the minute the bell rings. The students will then learn the routine of the morning class, such as taking attendance and what subjects will be covered in the morning hours.
Similar to the morning routine, students should know how to collect their things in an orderly fashion to end the day. Students clean up their desk, then help straighten up the room from the day's activities. The students will receive their homework assignments for the next day and leave the classroom in an orderly fashion.
This is something that no schedule can foresee, but there should be a proper routine that should be followed. It's important to already have a way in which the students will enter and exit the classroom. This would also be the way to exit during a fire drill, in a straight organized line. Inform the children that it's always important to take the drill seriously and never to think that it's just another drill, because it could be a real emergency.