204 Chevy Impala

I only have one light that comes on and it's under
the glove box area. All of the rest of the lights don't
go on is  there a way to see what voltage the head
light fuse is? And do you know if there is a way to
to fix a Chevy Impala stereo no audio no beeps
check the fuse it seems to be fine but the ground
needs to be fixed I want to know where the ground
wire is for the amp. The dome light fuses I
meanbecause we only got one light that works but
we want all the rest plus the trunk light is not
working is there a way to fix that too?