It needs data you may not have
Automated bidding across five surfaces learns from conversion volume. A store with a handful of sales a month is not providing a training set.
What to run instead
Search on your proven terms, tightly built, with a maintained negative list. It produces cleaner data faster and you can see what you paid for.
When to revisit
Once there is a steady flow of conversions, a healthy feed, correct values and a separate brand campaign. Then PMax has something to work with and something to be fenced away from.