This is known as a dactyl.
anapest
pyrrhus or dibrach
anapest
In that order, that's an anapest.
The term that defines a metrical foot pattern in poetry featuring one stressed syllable followed by two unstressed syllables is anapaest.
The anapest.
No, a couplet is a pair of rhymed lines in a poem or verse. A metrical foot is a unit of stressed and unstressed syllables used in metered poetry.
trochee
A foot.
dactyl
The term is "iamb." It is a metrical foot in poetry consisting of one unstressed syllable followed by one stressed syllable, such as in the word "begin."
That makes up a kind of metrical foot.