If my deductions are greater than my income and no taxes were withheld, does that mean I get nothing returned?

Not all deductions (such as Medical) count at 100%.

Unless you are eligible for what are called refundable credits, basically the Earned Income credit or part of the American Opportunity credit, you can only get a return for tax withheld.  With zero withholding, no refund.  If you have a loss on your business, that loss may be partly or all deducted against any other income to reduce your tax owed

Just a note that you are required to claim all of your self-employment income and expenses.

And if you have a negative taxable income then you may have a Net Operating Loss to deal with.