Nikon 5700 night shots

You gous did warn me but I don't get this night shot on P (auto mode).

I am shooting at night, trying to get half-time shots at night games. I admit
that I havent mastered setting my own exposures.

But why is using flash at 1/125 at f 4.2? I don't have a clue of the ISO

Would prefer may 1/30 or 1/60, and wide open...why does the flash go off at
infinity?

Have a screwed up the P mode too?

thanks guys

thanks guys