To create a product to sell on Google, you'll start by creating a product the same as you would any other WooCommerce product.
After you've created the base product, go to the Product Data area and to the Inventory section. Make sure you have it set to allow back-orders.
Sometimes stock updates aren't as fast as you need them to be. In order to cope with the delay and to be able to sell as much as possible, the option to allow backorders for this product must be activated.
Next, you'll select Google from the menu items. Click the checkbox to List on Google Merchant.
After that, you'll add your Listing Title, which, by default, is your product title.
Then you can add your Google Category and your Google Stock.
If you click the Open link by the Google Category option, it will show you the available categories to select from.
Then you'll select whether or not your product is an Adult product and the Condition the product is in.
Last, you can enter your Product Identifiers.
Beneath the Product Data area, you'll see options to add more information. Specifically, you'll be able to add a Google Merchant Product Description for this product.
Once you have created all your settings and added your Google Merchant description, be sure to Publish the product or Update it if it has already been published.