There is an extra T2125 on my return that I need to delete. I click on "delete," but it isn't removing the return. What else can I try?

If the T2125 has been automatically created by TurboTax because you had a T-Slip with self-employment income on it, then you will not be able to delete it without deleting the T-Slip. You would just need to enter the basic information on that T2125 if you have already put your other details on a different T2125.