$\mathbb{N}$ comes from the German "Natürliche Zahlen"=natural number
$\mathbb{Z}$ comes from the German "ganZe Zahl"=integer numbers
$\mathbb{Q}$ comes from the Latin "Quotient"= result of a division
$\mathbb{R}$ comes from the German "Reelle Zahl"=real numbers
$\mathbb{C}$ comes from the French "nombre Complexe"=complex numbers