Box 1 on my form 1098 is empty. I can't complete my tax return without providing something in box 1, but my 1098 box 1 is empty. What do I do?

I believe you are referring to Form 1098-T instead of 1098. 

Box 1 on Form 1098-T is for the tuition amount you have paid.  As it is shown as zero, which indicates you did not pay any tuition amount.  The questions would be:  did you pay any qualifying education expenses including tuition, books, and supplies out of pocket ?  If you did not, you do not need to file this form.  If you did, you can adjust the amount on the form. 

To adjust, here are the steps:

In TurboTax online,

• Sign in to your account, select Pick up where you left off
• At the right upper corner, in the search box, type in "1098t" and Enter
• Select Jump to 1098t
• Follow prompts
• On the screen, Type in the info from your 1098-T, check the box This is not what," Student' Name paid to school"

• Enter the actual amount you paid

• See the image below