What does a Pisces rising and Pisces ascendant mean?

Rising and ascendant both mean the same thing.

Pisces rising means you are shy, You're calm and you tend to day dream a lot. It also means you are very creative and idealistic .

Here's more information;

http://www.cafeastrology.com/pisces_ascendantrisin...

Pisces rising is another way of stating Pisces ascendant.

The ascendant or rising sign is how you appear to other people.

With Pisces you would appear to have the attributes or personality

generally given a Pisces sun. That is how you appear to others.

Your sun sign dominates but this is second or third in a chart,

depending on which author you read.

Neptune rules pisces. Are you referring to decans. The degree it places you would inherit those traits. But you would be netunish with a pisces rising