"δάδα" is literally a torch (not a flashlight). It's the flame at the end of a stick, a firebrand -- what Indiana Jones would use in the catacombs of some lost Aztec temple, or what Rambo used in "First Blood" to navigate through the mining tunnels inside the mountain.
A flashlight is called "(ο) φακός".
Is ένα only the greek for number 1?
No, the numeral has all three forms ένας, μία, ένα, just like the indefinite article.
The neuter form of the numeral is used when talking numbers only (e.g. one plus three = ένα και τρία), otherwise the grammatical gender has to match the word it refers to. So, if it's a neuter one, like κορίτσι, then yes, it's 'ένα κορίτσι'. For feminine and masculine words though, even when you mean to use the numeral and not the indefinite article, you have to gender match the words: μία γυναίκα, ένας άνδρας.