I am concerned that your students chat back and forth and ignore you.
This is rude and disrespectful behavior. It also distracts them from learning what you need to teach.
It sounds as though you need to be more firm with them.
You might start by having a candid talk. Ask your students if they want to pass your class. Get a show of hands. Who wants to pass? Dicuss the consequences of failure. What is likely to happen to these students if they fail your class?
If you don't have classroom rules and expectations, you should adopt them. You should also have standard consequences for students who fail to measure up. Students need to know what your expectations are and what what will happen to them if they fail to measure up?
For example - talking? What is your current consequence for talking? If you are simply saying "be quiet, please be quiet, I told you to be quiet ..." it should be evident that this isn't working.
What consequences are you allowed to impose? Does your school have a detention hall? Can you refer students to the headmaster or building administrator for punishment? Have you called individual parents to discuss your concerns? Can you keep students after school?
Not only should you have consequences for failure to follow classroom rules, but these consequences should be immediate. Students need to understand cause and effect. If they misbehave, if they don't do their homework, if they don't participate in class - what is the consequence?
Classroom management also needs to be consistent.
You can't impose a consequence when Charles loudly visits with others while ignoring Lucy who has done the same thing.
Classroom rules have to be for everyone. They have to be applied equally otherwise the lesson you are teaching the students is that they can (sometimes) get away with unacceptable behavior.
Teachers can't teach their students unless the learning environment is conducive to learning.
As to whether or not your test scores are normal - it really depends upon your student demographics.
I have taught in schools where 90% of my students scored in the top 5% of a standardized test. I have also taught at schools where most of the students have failed.
How have the other teachers done? Are the other teachers experiencing similar problems? If you are the only one having these problems, you will need to seriously reflect upon your techniques for classroom management and instruction.
Don't feel bad if this is the case. I know that you are a first year teacher and first year teachers typically have to grow into their jobs. Learning how to become an effective teacher is a process that generally takes several years.
Not to worry. You will get better as you develop more experience.
For now, you have identified a problem. It is now up to you to find a solution for making things better.
From what you have posted, the first step should be for you to take control of your class.