Red is Prussia, Purple is Austria, Navy Blue is Switzerland. That's an idea for starting regions.
Note: The two beige patches in what is now France are part of England, the green strip is France. The yellow blob in the middle is the HRE, I suggest that "new" nations be born here if possible, for convenience, or by having the player write a rebellion in one of the other nations. Also the two Blue patches up by Poland are the split region of the Teutonic Knights and the Yellow Islands in the Mediterranean Sea all belong to Aragon, the yellow triangle in what is now Spain.