The first syllable of "flower" is "flow."
Flow er
Captive is stressed on the first syllable.
The first syllable is accented.
The first syllable.
Flawless is accented on the first syllable.
The first syllable is accented.
The first syllable is accented.
It is not entirely clear whether you are asking which syllable is stressed or what the first syllable is. The stressed syllable is the first syllable: sev.
Footprint is stressed on the first syllable.
"Unfold" is accented on the first syllable. The stress is on the "un" syllable.
Flow - er
The first syllable is "A".