Welcome to the forum!
You can substitute yarns as long as they are the same weight and you get gauge, for the most part.
A cotton sweater will be less stretchy than a wool one, but I think with the acrylic blend, you won't have the problems with a pure cotton sweater--cuffs and such can stretch out and not spring back.
"Trust the pattern!"
Time flies like an arrow, but fruit flies like a banana.
Hop aboard while we follow the cloud-covered van of knitting harmony, man!! Woooo!! --Hedgehog
IngridKH on Ravelry