Home fans.
3rd base dug out.
The left side if you are if are coming in from the main entrance
The Chicago Cubs are a professional baseball team from Chicago, Illinois. The Chicago Cubs' home field is Wrigley Stadium, which is located on the north side of the city.
That expression came about around 1947, and is related to America's great pastime, baseball. "Left field" is the left side of a baseball field, looking out from home plate. David Wilton states that the expression probably came into being from the idea that a ball fielded from left field was unlikely to be thrown to home plate in time to put a runner out. [Link below.]
First base line
WEST, generally
There is no rule that states the home dugout needs to be on a particular side. This is completely up to the owners/management of the team
The home field for the Oakland Raiders football team is Oakland-Alameda County Coliseum. The field is located at 7000 Coliseum Way in Oakland.
Wrigley Field, where the Chicago Cubs play, is across town on the North Side.
Because when they form it, they usually have it dug out of the ground on the side of the baseball field, hence the term "Dugout".
Third base side