"Nada" vs. "Ningún"
when do you use ningun
When you can count the things that there aren't any of. "Ninguna oportunidad" = "not a single chance" but intrinsically "oportunidad" is numerable; you can count how many you've had etc.
"Nada" on the other hand is used for things that are either not measurable at all or that don't come in ones and twos.
Ninguno" means none, not any, no, etc.
"Nada" means nothing.
Ningún is used instead of ninguno before singular masculine nouns (e.g. ningún hombre = no man).