Knitting newbie need help

Hey all I am pretty new to knitting and so far have only braved hats and scarves. I am now knitting my first baby cardi and my pattern has asked to ‘dec 1 st at neck edge as before in next and every foll alt row’. my question is do i take ‘next’ as literally the next row or the next row after this? my gut is saying the very next row i do but im afraid of ruining all my work lol please help a gal out, thanks

Welcome to KH!
Make the decrease on the next row. Presumably, you’re at the end of one row now, so the dec goes at the neck edge on the row you’re about to start.
The difference of one row isn’t going to ruin a sweater or neck shaping.