A folder
or
One folder
depending on context
A 'carpeta' is a folder.
Carpeta can mean a folder, a file, a label, a wrapper.
un escritorio/pupitre una carpeta
it means three-ring binder
It means, "I need a calculator and a ring binder for the mathematics class."
buy//he/she/you buy(s) a tablecloth/portfolio/letter-file/writing-desk/small curtain
Carpeta de argollas. that's binder, folder is carpeta.
Una carpels in English
Like a manila folder? That's called una carpeta.
"Una botella" means "on bottle" in English.
"Una cuadernos" is not grammatically correct in Spanish. "Una cuaderno" would mean "a notebook" in English.
Una bolsa is spanish for "a bag"