I am a student with very little income. Turbo tax says that i have to upgrade to deluxe because I have additional tax on excess contributions or deduction (form 529)?

Did you receive Form 1099-Q concerning a 529 plan?

Yes, you would have to upgrade to deluxe if you had a taxable distribution from a 529 plan or even entered a 1099-Q.

But, if you know that none of it is taxable, you can just not enter the 1099-Q, and avoid the upgrade. 

You can just not report the 1099-Q, at all, if your student-beneficiary has sufficient educational expenses, including room & board (even if he lives at home) to cover the distribution. When the box 1 amount on form 1099-Q is fully covered by expenses, TurboTax will enter nothing about the 1099-Q on the actual tax forms. But, it will prepare a 1099-Q worksheet for your records. You would still have to do the math to see if there were enough expenses left over for you to claim the tuition credit. You also cannot count expenses that were paid by tax free scholarships. You cannot double dip! 

On form 1099-Q, instructions to the recipient reads: "Nontaxable distributions from CESAs and QTPs are not required to be reported on your income tax return. You must determine the taxability of any distribution."