Why does Segismund behave so badly during his first time at court?

C. He is overwhelmed with freedom and the new sensory expriences.

We need to consider that Segismund had spent a lot of time enclosed in the tower as a prisoner and he is freed because the country is at the middle of a civil war and the people want to crown their rightful king, so he is freed. Having mentioned this, when he is for the first time at the court he is simply overwhelmed with his freedom and all the sensorial new feelings he is going through.