If it says to work one row in st st, then either knit or purl the next row, whichever will maintain the stockinette as it's been established.
Later on for the two rows, again, just work for two rows in the pattern as you've been doing.
"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