The hallmark of the American justice system is that everyone is presumed innocent until the prosecutor proves otherwise. This means that the judge and jury must give you the benefit of the doubt and view the prosecutor's arguments skeptically until they are supported with evidence. This theoretically means that you have the advantage. In a perfect system, if you believed that the prosecutor was totally wrong, you could sit back and refuse to submit any evidence or arguments since the burden is entirely on the prosecutor. In reality, this probably isn't a good idea.
The standard the prosecutors must meet to prove that you are guilty is known as "beyond a reasonable doubt." This means that the prosecutor must demonstrate with evidence and reasoned argument that there are no reasonable doubts that you are guilty of the crime.
Many people mistake this to mean that there are no doubts as to your guilt, that isn't true. It only means reasonable doubts. There will always be doubts as to whether you committed the crime because the trial is being conducted months after you were arrested. Memories fade and evidence goes stale. There are always doubts.
As the prosecutor produces more and more evidence, this means that the scales are tipping against you. So you start to have to produce some of your own evidence to explain the situation or assert your innocence. Many people do this by establishing an alibi. An alibi is proof that you couldn't have committed the crime because you were somewhere else. You can use receipts, security footage, witness testimonies and more to demonstrate your absence.
If you were charged with a crime, then you may want to use a phone call to contact a defense attorney. Depending on the severity of the charges, you could be facing significant fines and possibly prison time. A lawyer can review your case and help you decide on the best course of action to defend yourself.