I am International Student. I did not fill out the tax return for 2018 because I did not have SSN.I paid $11150 in tuition and material expenses. now I am graduate assist

If you are still on an F-1visa and have not stayed within the US for more than five years, you are considered as a nonresident.  Nonresidents are not allowed to claim any education tax credits or deduction.  

If you have already stayed within the US for more than five years by the end of the year 2019, you are a US resident for tax purposes.  You can claim an education credit or deduction. 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