Does using different ply's matter?

right now, i’m knitting a green shawl with 8 ply wool. i’ve just bought some more wool and suddenly realised i bought 12 ply instead of 8. does it matter or should i not worry about it and use it anyway?

i’m very new to knitting so i apologise if my questions are bit on the silly side!!

Does it knit at the same gauge?

ummm, i don’t know what that means. yep, i’m so new to knitting it’s disgusting! i’m not following a pattern, i’m just knitting a very large rectangle and calling it a wrap/shawl lol. i’m taking the cheaters route!

look at the labels for the two skeins of yarn. how many stitches per inch do they say?