Customer Journey Map for a Retail Store

I want to run a Customer Journey Mapping(CJM)exercise. From what I understand you conduct CJM exercise for each persona. We don't have any persona's in place. This work won't be ready until the end of the year, but I need to start in the next month or so. I was thinking of creating proto-personas/provisional personas.

Does this approach sound OK?

Also, do I need to conduct an Empathy Mapping exercise for each persona or can i just perform the CJM exercise?

Thanks