How do I measure improvement initiatives?

As a Shopify store owner, I'm constantly trying to optimize my e-commerce performance, but I'm struggling to understand which improvements actually move the needle. Every change I make feels like throwing spaghetti at the wall. I've tweaked product descriptions, adjusted pricing, changed ad creatives, and modified checkout flows—but how do I definitively know what's working? My gut tells me I'm missing critical insights. I need a systematic way to track the impact of my initiatives that goes beyond vanity metrics. Right now, I'm tracking overall conversion rate, but that feels too broad. I want granular data that shows me exactly how each optimization affects customer behavior. Am I improving product page engagement? Are visitors moving more smoothly through my funnel? Are my changes reducing cart abandonment? Without clear measurement, I'm essentially running my business with blinders on. I need a robust framework that helps me understand cause and effect, allowing me to make data-driven decisions that genuinely improve my store's performance. The frustration is real—I know improvements are possible, but I need a reliable method to identify and validate them.