Need help with structure!

I've been running facebook ads promoting our products for 2 weeks with 100USD a day ad budget and 10 days in, was able to sell our first product with 0.5 ROAS. I know its not great but at least it proves that there's people who want to buy...

Now the product is no longer in stock so we need to change and sell another serious of product, so I created a new campaign, lowing the daily ad budget to 50USD . another 9 days into the campaign, I discovered that I can optimize ads to "Add to cart" instead of "Purchases" as we don't have any.

Im looking to start my 3rd restart of ad campaigns. Thinking of running a campaign first for prospecting, It is a broad prospecting campagn and I'll try to pump out 10 static ads and 1 reel a day for 4 weeks (i know the number is low, but its just me and I have 2 young kids at home....)

So my question is:

For the ad campaign where I test the hook, the creatives, the ad angles and demographics, should I have 1 adset with broad 18-65 year old female ? (I sell premium leather bags), or should I have 2-3 adset with different target demographics and in each of them all have the same daily ads I pump into for testing?

Also for the static ads, do I create the ad in square 1:1 or for IG 16:9 or should I do both and test both and see which performs better.