I don't know of any requirement for a receptacle on the outside of a garage. There is a requirement that the entrances be lighted. One light can serve both entrances if they are illuminated by one light.
You need to take care about the terminology of "outlet". An "outlet" is defined in the code as any point at which electricity is supplied (but not a switch), and that includes places for mounting light fixtures. An outlet that you plug a cord into is properly referred to as a "receptacle". There is a requirement for an "outlet" to supply a light for an entrance but there is no requirement for a receptacle.
If you have an outdoor receptacle the current code is that it must have in-use weather protection. That could be either an in-use cover or it could be under an overhang that provides rain protection.
Outdoor receptacles need GFI protection.