WIFI konfiguration

[e-sailing]

I see the WIFI openplotter in the configuration für WIFI on the ipad, but can not connect because wrong password or network failure

That's your problem.
You aren't connected to openplotter. You can set the AP password on the network tab. Default is "12345678".

On the PI I see only two blue arrows in the top and no wireless interface found.

That's OK. The wireless interface is bound to the AP.