If I have a straight clamp and want to use left wing fletch do I need a left wing indexer? Thanks!

If you have adjustable nocks, no.  You just twist the nock after you have fletched the arrow until it is in your preferred orientation.

With a glue-on nock, it is a little more tricky.  Even if you have the correct indexer, you are not guaranteed that the finished arrow will have the nocks exactly where you want them, because Bitzbenbergers do not have a way to fine-tune the nock orientation like some other fletchers do.  What some people do is to fletch the arrows with the nock pressed on but not glued, and then orient the nock after it is fletched before gluing it.

Simple answer no. Just offset the adjustment a few degrees to the left.

Thanks!