What does it mean when it says...."Wrong side knit (even) rows: Purl"
It's just giving you information that all odd rows are the WS and will be knit; even rows are the RS and will be purls. This is reverse stockinette because the RS rows will all show as purls.
When do you start counting odds/evens? Is the first row the casting on row or the first row of actual knitting?
The cast on isn't counted as a row, it's the first actual row of knitting that's Row 1.