Welcome to ERPNext Christof
Yes fresh installs can be a challenge, that can easily discourage first-timers.
I opt to run a VM instance if that is an option for you?
For eg this post reports success Can we get upgraded version of VM? - #3 by asharamseervi
Efforts to improve installs is one among many goals.
I hope you persist with your effort, to discover the merits and rewards of this ambitious product.
cheers