I am student teaching in a self contained special education class. I am assumming that is the type of class you are going to be taking over. The first thing you have to do is set up a discipline policy with your students. Let them know you mean business. You may want to set up individual contracts and a setof general class rules.
Kids are never too old to have a set of class rules.
Let them know the consequences and be tough and tstickto the rules. You may have to spend a little bit of your own money but it will be worth the piece of mind. Let them kow that you can be their friend also. As far the curriculum, you may want to ask the other teachers in rhe general education classes what they are doing and assume that you students may be a little bit behind. If the past teacher left any old plan books look at them.