Finding an apartment in Munich from early August!!

From 01.08.2018 I will start working in Munich, thus, I want to find an apartment to live in. I am an open-minded and easy-going person, never smoke and be drunk. Personally, I prefer to stay silently. Relaxing myself by reading and listening to music at home is my most weekend activities.
As my work place is on Frankfurtringe, I would like to rent a flat that is close to it, or somewhere is easy to get U2. Of course, the flat in city center will be welcomed.
At the moment, I live alone. However, from 2019, my wife will be with me from Australia. Therefore, the apartment should be available for 'anmelden' 2 persons, and the living space should be enough to hold a couple. In addition, it is even better that the energy consumption of the flat is not high.
If anyone has such nice flat, please contact me asap, because I will be in holiday from 5 to 23 in July.