All 3 of my W-2 forms (all 3 are from different employers) are completely blank on the federal income tax withheld box. Any reason as to why this may have happened? I live in Florida if that makes a d

That likely was because you worked for a short time for each employer or earned so little that the employer did not withhold any federal tax.  There would be no state tax in FL, since FL has no state income tax.  But.....when you add up all the income, it may turn out that you owe.  Enter the W-2's one by one into the same tax return to see how it turns out.   

ALL of your W-2’s must be entered on the SAME tax return.  After you enter the first one, you click Add Another W-2.