“فَ” (fa)a joining word meaning “then / so.” It connects this word to what came before.Corpus grammarCONJ — prefixed conjunction fa (then / so).
“شَٰرِبُونَ” (shāribuwna)means “And will drink” in this verse. It is a noun form. a word describing a doer or an action in progress. Its opening “mu-” is part of this word pattern, not a separate added word.Corpus grammarN — masculine plural nominative active noun.