Hello Hannes,
there are already some posts on this.
If you are going to install irrigation, then for the entire garden/lawn.
Your question cannot be answered in this form. There are some other steps before that.
1. Forget Gardena (especially the multi-area sprinklers). After 1-2 years you will rebuild...
2. The valves/circuits are not visible on your drawing.
3. Sprinklers need to cover each other.
I can recommend the Hunter rotators with a pressure-regulating housing. Pipes in PE-HD dn32. Not the soft, overpriced dn25 from Gardena.
In principle, you should look for a pump with >4bar and >5m3/h.
Install an air pressure connection for blowing out in the valve box.
Take the datasheet of the Hunter rotators, distribute the sprinklers on your property (mutually overlap!).
Enter the flow rates into a table. Now you can form circuits according to water demand, location, flow... This way you will get the required number of valves.
How do you want to control? Hunter Hydrawise is practical as a standalone.