How do I benchmark my checkout speed?

As a Shopify store owner, I've become obsessed with understanding why potential customers abandon their carts. I know checkout speed is critical, but beyond basic page load times, I'm struggling to get a comprehensive view of my store's performance. Every second counts in e-commerce, and I've heard that even a 100-millisecond delay can tank conversion rates. My current setup feels like I'm flying blind—I'm tracking some metrics, but I don't have a holistic understanding of how my checkout compares to industry standards or my competitors. I'm worried that technical friction is silently killing my sales, and I need a systematic way to diagnose and improve my store's performance. Is there a way to get granular insights into checkout speed that goes beyond surface-level metrics? I want to understand load times, interaction responsiveness, and how these technical elements translate into real-world conversion impact. My goal isn't just to have a 'fast' store, but to create a seamless, friction-free shopping experience that turns browsers into buyers.