From this apartment, you will reach the Charles Bridge in less than 10 seconds. Take a walk in the morning and see the bridge before the crowds. Also, it is just a few steps away from the Old Town Square.
In the vicinity, there are many grocery shops, and very good restaurants. Please take a look at my personal recommendations, because it is easy to get lost in the myriad of places. In the list, you will find places which are affordable and also serve very good food (traditional Czech as well as international cuisine). The variety of restaurants in the center is overwhelming so it (email hidden) to know where to eat.