Our v8 doesn't like anymore

Yesterday we drove quite normally, it all went well, except that the tank clock lit up although we were full the day before.
And today it doesn't start, the starter turns quite normal but that's all

In the third attempt the oil pressure indicator has lit up, the analog spins yes sowiso (last already posted), but the oil level is fine.
My husband was already angry about our problem child today
Do any of you know these symptoms??
Greetings from Innsbruck
Kathy
