Electricity costs for a KfW QNG 40 house

The question for me is, what do I roughly pay monthly for electricity?

With 200€ heating costs per year, the question arises,
is the house located in Germany or in the Mediterranean region?
Does the house have underfloor heating with water, or how is it heated?

You are asking the wrong question. The correct one would be: What are my heating costs in a 120sqm new build with a heat pump?

You already know the electricity costs for your private use. Those don't change with a different property.
Heating costs = electricity consumption is the only unknown. And that depends on your behavior as well as the heating system design. At 25 degrees room temperature and windows open at the same time, because "one" always absolutely needs fresh air, consumption will differ significantly from 21 degrees and the use of controlled residential ventilation.
Calculate with the already mentioned 1,500-2,000 kWh.

Then simply calculate with an electricity price and you will know what your maximum electricity costs are. Maximum, because you still have to deduct photovoltaic yields. With my 10-panel system without storage, I have about 25% self-consumption, so around 2,500 kWh (including e-car as mentioned). If you have storage, you get 45% self-consumption, so about 1,800 kWh self-consumption that you can subtract from your total consumption.

P.S. Please let go of 40 QNG. That says absolutely nothing about the actual consumption. Just say "new build" with photovoltaic and heat pump.