First, I really appreciate that a 9th grader actually wants more laws! That is not the norm. However, a fact of the matter is this, approximately 80,000 new laws are created in a year in this country at the Federal level. The highest law of the land in the United States is the Constitution. The Consitution applies to those citizens of the U.S., not the world.
It isn't more laws that make the world better, it is people who follow the basic principles of human decency, common sense and fair play that make the world a better place. In a world of difference in every possible way, laws are only relative to the specific group who created the law. Laws in one nation or culture may not apply to another nation and culture.
International Law is a difficult realm to cordinate around the world. Unless those countries or Governments agree to follow the laws that the world establishes, the laws can not work.
The world is a better place by those who follow the laws of their land, even if those laws are seen as "unconstitutional" when measured against our own highest law of the land. It is not the amount of Laws, it is the type of laws.
In this country, it is not the laws that make us a great nation, it is the process that provides for the lawmaking. The process is not perfect and we know that because our justice system is overflowing with lawbreakers, law challengers and law changers.
Following laws, not making them, lends to a better world.