Thanks for looping in with the conversation.
To correctly track your inventory in QBO without affecting sales, you may refer to what Qbteachmt and Reginamarie have discussed above. The items you add will not be treated as sales unless you add them to your sales transactions.
In your case, you can create a custom income account for the products you're adding that should not be part of your company's revenue. To get help setting up the sales account for your non-sale inventory items, I'd recommend consulting an accounting professional. They can provide you with the best legal and accounting advice for your inventory management in QuickBooks Online.
Please feel free to reach out to me if you have any more questions with QuickBooks. I'm always here to help you whenever you needed me.