I'm Ava from Shopify, I'd like to help here!
From the screenshots you shared, it looks like you've enabled multiple locations on your old site, but it has not been enabled on your new site. A location is a physical place or an app where you do any or all of the following activities: sell products, ship or fulfill orders, and stock inventory. Multiple locations allow you to track inventory and fulfill orders at all of your locations.
Enabling your store to track inventory across multiple locations can’t be undone. After you enable locations, you can’t switch back to having a single inventory quantity for multiple locations. So this means you would not be able to make your old website look like your new site. Your old site looks like it has multiple locations enabled, so it now cannot be disabled.
Can I ask why you would like the old site to look like the new one? Were you having trouble editing the product variants on your old site? If that is the case, then we can help! Editing variants for a store with multiple locations is a little different, so there is a detailed guide you can follow here that will show you how to edit.
Let me know what you think, I'm happy to keep chatting here!
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