I can share additional information, @Brennan Morrow.
When you integrate QuickBooks and Square, it does not automatically copy over your inventory list from Square. What you can do is to set up your QuickBooks with an identical item list by exporting your Square list into QuickBooks. Once completed, you can record your sales and decrease your inventory items. Just make sure that the item name and/or SKU in QBO matches what you have in Square.
As for using a bundle item, @Rustler is correct! The Bundle feature in QuickBooks allows you to group items sell together into bundles so you can easily add multiple items to transactions. However, you'll still have to do the inventory tracking per item included in the bundle. You can check this blog for more insights: Introducing QuickBooks Bundles.
You can read through these articles to learn more about Square and QuickBooks Online integration:
Feel free to leave a post if you have other questions. I'm always here to help.
