The cast on row is not the right side or the wrong side yet.
That is determined by the pattern.
Some patterns say that the next row is the right side. Others specify that the next row is the wrong side. Some patterns don't tell you which side is which, and you'll be able to see which side is the right side after you get started.
The right side is the side that will be facing the public. For example, the outside of a sweater is the right side. The inside of a sweater is the wrong side.
Some patterns don't have a right side, because they are the reversible.
Just trust the pattern, and wait to see what it says.
Good luck with your knitting!