German keyboards use QWERTZ: Y and Z are swapped compared with English, and the umlauts Ä, Ö and Ü have their own keys on the right side, with ß next to the zero. The home row for the right hand ends with Ö and Ä.
Typical difficulties
Reaching Ü, Ö and Ä with the little finger without looking.
Capital letters at the start of every noun, which means many more Shift presses.
Switching between Z and Y if you also type in English.
Use type by position to practise German even on an English keyboard, and the adaptive mode to drill the letters you miss.