Need further instruction re Pinecone index settings

As a Pinecone newbie hoping to use this extension, I need some more detail about the parameters for the index. Specifically: what dimensions should the index have, and what metric should it use?

Thanks!

I'm also getting an error that my OpenAI API key isn't set, when the setting is in my settings.json user settings file and the key appears to be correct (spellbound.openai_api_key)