Use a reward system for good behavior. It can be stars, badges, responsibility or prizes. Make it competitive by awarding the person with the most rewards at the end of term an extra prize. Have a chart on the wall that clearly shows how everyone is progressing. Mention it at parent-teacher conference events.
If the class gets too noisy and disruptive, use the "Countdown" system. Start at 20 and work backwards; if the class hasn't quietened by 10, they lose five minutes of recess. If they are still not quiet at 20, then this is not working and you need to use a different strategy. You can countdown in different languages and get the class to join in, adding to their learning.
Sit the children in a circle and discuss class management. Ask them their views and what bothers them in class. There will be some shy children so encourage each member of the class to air their views. Make notes and work around their comments. Some children may want to take responsibility for helping with class management.
Often there are one or two particularly disruptive students in a class. Instead of punishing them, give them responsibility. Invite them to put the reward stickers on the chart or help others if they are particularly good at a subject. Make them a classroom assistant, and give them lots of praise for the constructive things they do.