Facebook and Instagram ads, from the darkness into the light

I’m giving some different Facebook and Instagram ads a try. I found the most recent live biz coaching with Brooke to be extremely helpful. Here’s my follow up question. Let’s say I try ad #1 that gets minimal clicks for x-thousand if impressions. I don’t have much info from the void about what wasn’t working about it. So let’s say I try ad #2. And so on and so forth. Kind of fumbling in the dark. That’s ok, but what’s reasonable about budget/length of time/# of impressions before moving on from ad #1, then to #2, etc.? How long to give each one before it’s time to try a different ad, copy, parameters? My sample size with each of my tries since Dec. has been so small that I don’t know. But, the two women who responded to my direct mail piece sent to 1100 carefully targeted women were like YES, this is what I need. So I have some information about what’s working, but am having difficulty translating that to the Facebook and Instagram setting. I want to be self sufficient here, so I delayed asking this question. A wee bit of guidance would be so helpful. Thank you.