First off, congratulations on understanding the importance of analyzing your previous campaign's performances. Too often do we throw advertising dollars into paid advertisements without fine-tuning the process along the way.
I think a terrific first step would be to try and understand why your ads aren't converting as high as they should be. This guide here does a solid job addressing four potential reasons. It's also quite comprehensive by getting into some of the nitty-gritty concepts of Facebook advertising. Additionally, we have a Facebook Ads for beginners guide that will be very useful. Chapters 4-9 will be especially useful for what you are looking for.
Also, you will want to establish a deep understanding of your ideal buyer's persona. One of my favourite resources on this topic can be found here. This is such a crucial step in all of your marketing initiatives (Facebook ads especially) as it will set the tone to how you approach your customers and leverage your ability to connect and hopefully engage with your business.
I hope all of this helps, Kyle! If you have any other questions don't hesitate to reach back out.
If you are 100% sure your targeting is working then you need to change your creative (images and ad copy). Those are the two levels you have on Facebook and Instagram. If you are not seeing those add to cart convert into a sale. Change your creative and keep testing that. Hope you found this helpful, if so please click "like" below to let me know.