You have to look at your 1040 and schedule A to see why it's not affecting your refund or tax due. Maybe you are already getting back all you can and more deductions won't increase it. Some Deductions are limited. Or you still owe for something else. Also after you reduce your income to zero there is no more refund to get back but you still may owe for other things like self employment tax or the 10% early withdrawal penalty from 401k or IRA accounts.
How to print your return before filing
https://ttlc.intuit.com/community/printing/help/can-i-print-a-copy-of-my-turbotax-online-return-befo...
