How can I identify if there's a specific step in my checkout process where most people are leaving?

I've been running my Shopify store for two years now, and while our traffic has been consistently strong, something's been bugging me: our checkout completion rate seems frustratingly low. I can see people adding products to their cart, but they're dropping off somewhere in the purchase journey. It feels like we're leaving serious money on the table. Every time I look at our analytics, I get more frustrated—I can see the potential revenue just slipping away, but I can't pinpoint exactly where or why. Is it the shipping costs? The payment options? The form complexity? Are customers getting cold feet at the last moment? I've tried different strategies, but without a clear understanding of where exactly customers are abandoning their carts, I'm basically throwing darts in the dark. My ad spend is significant, and watching potential customers bail out mid-purchase is not just disappointing—it's costing me real money. I need a systematic way to understand these drop-off points, something that doesn't require me to be a data scientist or spend hours manually analyzing complex spreadsheets. I want clear, actionable insights that can help me streamline my checkout process and recover those lost sales.