Do I need to have an ontological and epistemological position for my qualitative interview based study?

And secondly, does anyone have a concise easily written document that can help explain all the difference stances? It is so mind boggling!

Yes. The fact you are doing an interview based study already implies you have an epistemological stance.
Ontology: what exists in the world?
Epistemology: How do you know it exists?

Yes you do - I can recommend Mark Easterby-Smith, R Thorpe and P Jackson, Management Research, Sage 2012. It's good even for non-management research (like me).