Hello! Your question was a little confusing but I understood that you want to know how could a nation benefit and/or improve its economy by following the Mercantilism theories?
If that’s the case, first you should know that Mercantilism is an economic theory practiced between the 16th and 18th centuries, based on a system of trade. Basically the government would manipulate the economy in order to create a favorable trade balance between nations.
At that time, supporters of this theory believed that they could strengthen a nation’s economy by controling colonies, establishing restrictions on imports, having generous reserves of gold, silver and foreign currencies and limiting wages of the working classes in order to benefit the merchant class, just to name a few.