Was the American Revolution really started in the North, fought in the South, and won by the French?

The American Revolution (1775–83) was a long and complex war. Your statement contains three assertions and is, in large part, true.
The war did indeed start in the North. Boston had always been the center of anti-British sentiment, so this was not too surprising. The war's first battle, an American victory, was at Lexington and Concord. Then the British won a costly victory at Bunker Hill. Next, the Americans forced the British to evacuate Boston by placing cannons on nearby Dorchester Heights. Canada was also the scene of fighting as Americans tried to capture parts of it.
In 1778, the British decided to focus on the South. They believed there were many Loyalists in that region who would help them. Savannah and Charleston fell to the British in 1778 and 1780, respectively. British control of the South was contested only by American guerrillas.
In 1781, France helped win the decisive victory. The British were surrounded in Yorktown. The French Navy prevented escape by sea. The French Army bolstered George Washington's Continental Army. The British were trapped and had to surrender.