Pi with IQAudio Pi-DigiAMP+ doesn't start

I’m new to this forum and a little bit frustrated. I bought a Raspberry Pi 3, a IQAudio Pi-DigiAMP+ and the official Raspberry Touchscreen.
After assembling everything I started the combination. On the Touchscreen I can see that the system is running up until nothing happens anymore on the screen. I the tried to start the GUI via my Safari browser, but nothing happens. The green LED which indicates muting of the amp is still lighting.
And yes the Pi is connected to my network via LAN.
What the hell am I doing wrong?
Thank you so far

Problem fixed! Made a new sd-card an started the whole process again. Now it works!

Great!!! Could you share some pics of your system? It must be looking great!