How bad did I mess up? I am a new amazon seller and still trying to figure out this monster. Any advice is appreciated

Hey everyone! Any advice would be very much appreciated!!

The Situation: I am still trying to figure out how amazon ranks me. I decided to sell some items on amazon that were just laying around the house that i had bought for a previous business that didn’t work out. I had 100 of these items and put them in boxes of 5. I did some PPC adds and ended up selling all 20 boxes of 5 within 17 days. With my add spend i ended up in the red which i expected for my first round. The items sold slowly at first by the last 3-4 days they went quickly. I had more “organic” sales by the last 2 days then i did sponsored sales. Seeing that i decided to go get a ton more of these items and try on a larger scale, hoping that i would make money this time.

Possible issues: So here’s where i think i messed up. Since they went quicker than i expected, my inventory was out of stock for about 3 days. I understand this messes up my ranking?

When i finally restocked i opened another automatic campaign and sold 2 within a couple hours. But then i decided to optimize my post (I posted more pictures, changed some keywords, and put some new descriptions). After i did that, i haven’t had a sale in about 2 days.

So here are my questions: Did i completely mess up by changing something that may not have been broken (new PPC add, changing keywords and pics etc…)

Did i mess up my ranking that bad just because i was out of inventory for a few days?

Does anyone have any advice on how to fix this? Maybe run a sale price on these items for a few days?

Thank you to anyone who can give me any advice. Trying to learn how amazon works has been tough, and i am doing my best to figure out best practices.