When you become a solicitor, you become part of a profession with some very important ethical obligations.
Your highest obligation is to the courts and justice. You are an officer of the court and that means you must act at all times in the way that ensures that the court is supported and justice is done. This is not limited to litigation. It applies to all types of practice.
Your clients are owed your undivided loyalty, subject to your obligation to the courts and justice. You are their fiduciaries and must ensure that you can act in their best interests.
Your colleagues are owed your professional support. For instance, you must be courteous to them at all times, as indeed you must be courteous to everyone.
These ethical obligations have a very long history and are well established at law. To assist you, there are Conduct Rules which set out some of these obligations, which you can consult on NSW legislation website.
The Law Society has also published a Statement of Ethics.