Munich is a wonderful city to visit that has some amazing architecture like Marienplatz and the town hall center.
It is one of the friendliest cities in Europe that I have ever visited, and the Victuals Market area is one of the MUST VISIT during the day and at night in Munich.
The Theatine Church is quite a site that is quite popular that is easy to walk to and find with its bright yellow color. Many people like to visit to just hear the massive organ.
You may not be able to see the snow in September/October at Oktoberfest, but if you get to visit Munich in the winter, it is so serene and calm place to visit and take walks in the soft snow.
Linderhof Palace is a great place to visit in the summer or winter even if it is snowing! it gives you a taste of both Bavaria and the historical culture of the area.
and yes, the zoo in Munich is quite good and a great way to spend an afternoon if you have some free time. The Hellabrunn Zoo is quite affordable and easy to get to on the train. Bright pink flamingos in the winter is quite ironic isn’t it?