“worshiped before Yahweh.” That is, worshipped at the Tabernacle, almost certainly in the presence of the High Priest. In that sense they did worship before (or, “in the presence of”) Yahweh.
“Elkanah knew Hannah his wife.” An idiom for sexual intercourse. See commentary Matthew 1:25.
“remembered her.” “Remembered” is an idiom for “acted on her behalf.” See commentary on 1 Samuel 1:11.