First, in measures 1-3, there is a pedal point (organ point) in the left hand, consisting of tied whole notes. One can imagine a thick bass pipe sounding on a pipe organ, so this section should be played forte. Otherwise, the bass will not sustain sufficiently.

Next, looking at measures 9-11, there is an ascending sequence, leading to a cadence in measure 12. Furthermore, in measure 13, both hands present the theme, and in measure 14, 16th notes appear, increasing the tension. Therefore, simply put, measures 9 through 16 should be played forte.

If measures 1-3 are forte and measures 9-16 are forte, it becomes essential to reduce the volume in measures 5-8. Therefore, although measures 5-8 are in G major, please play a beautiful G major with reduced volume. Maintain piano (p) until the first beat of measure 9.

Furthermore, regarding the right hand, the highest note in measure 4 is E, in measure 5 it is D, in measure 7 it is C, and in measure 9 it is B (H in German notation). Since the notes descend scalewise, try applying a diminuendo as the notes descend.