I need to edit parts of this return

Which part?

inventory

inventory

Please follow the instructions below to edit your inventory in self-employment:

1. Login to your TurboTax Account 
2. Click "Take Me To My Return"
3. Click "Federal" from the left side of your screen
4. Scroll down to “Self-employment income and expenses” and click "Edit/Add"
5. On the "Your 2018 self-employed work summary" screen click "edit" next to your self-employment work
6. Scroll down to "Expenses" and click "edit" next to "Inventory"

Stimulus payments 

When you reach the end of guided tax preparation the system will ask how much you received for stimulus payment number 3.  If you need to get back to this place simply click on deductions and credits and follow the same prompts you followed in originally filling out your return and you will get back to the question about the stimulus.

IF YOU ALREADY FILED YOUR RETURN then you should not be editing your return yet, not until after the return is processed.