thanks to hubaiz. the small detail (sudo apt-get install git) helps a lot.
now the ddserver runs on the raspberry pi zero w as a standalone access point.
without restarting (sudo service dhcpcd restart) it is possible to install remotely (only with PuTTY).
i have chosen RASPBIAN STRETCH LITE as my operating system. i connect my nikon d800 with an usb b micro 2.0 to b micro 2.0 cable.
another note: to set the ip you have to press the network connection button in dslrdashboard for a long time.