When you knit every row, you're supposed to have a ridges on both sides.
When you knit on one side, a purl row appears on the other. So when you knit every row, as you turn it back and forth, you're seeing the knit side you knit and the purl side that appeared on the back. This is what's called garter stitch.
For stockinette stitch, where there's a smooth side and a bumpy side, you knit one row and purl one row. All the knit v's are on one side and all the purl bumps are on the other.
You didn't do anything wrong.