Serbia is the *only* country to win on its debut entry (if you ignore its entries as part of Yugoslavia). Even in 1956, Switzerland won with its second song of the night; their debut entry was "Das Alte Karussell", which of course didn't win.
Personally I would say the best-ever debut performance was Poland coming second in 1994, as Poland had never competed before under any name.
I would suggest also changing the one about "nul points" to the first ever *entry* to receive nul points, rather than country, as really all those countries got nul points at exactly the same time (i.e. when Monaco's jury finished their voting).
It is true that this is rumoured but until there is nothing officially true...
Personally I would say the best-ever debut performance was Poland coming second in 1994, as Poland had never competed before under any name.
I would suggest also changing the one about "nul points" to the first ever *entry* to receive nul points, rather than country, as really all those countries got nul points at exactly the same time (i.e. when Monaco's jury finished their voting).