Get your taxes done using TurboTax

 You can enter each form, in the right place. Let's make sure this is all one business on a single business return the way it should be. Your forms are in the wrong place since you are being asked about inventory with each form. Do not enter anything on the main income screen. If you did, delete those forms.

Go to Business, select business income and expenses

As you enter the business information, it will ask about 1099's.

Income:

All of your 1099-K income should be entered inside the business. There are no inventory questions when inside the business while entering the forms.

After entering all income, select that your business carries Inventory. Then go through entering the inventory for your business.

After inventory, you can enter other business expenses.