Start doing some homework and get your W-2's. You can still prepare your 2018 return--it will just have to be mailed. E-filing is closed for 2018. After you have prepared and filed it you will have what FAFSA wants.
W-2's come from your employer, and they have until Jan. 31 to issue it. You might need to phone, drop in, email and/or snail mail an old employer to make sure they know where to send your W-2.
https://ttlc.intuit.com/questions/2561916-how-can-i-get-a-copy-of-my-w-2
Other ways to get W-2’s:
Pay Social Security $86 per W-2:
You can get a wage and income transcript from the IRS: It will not show the actual W-2, 1099’s, etc, but will show the income information the IRS received. It will not, however, show your state information. It will only show the federal information.
https://www.irs.gov/individuals/get-transcript
Online preparation and e-filing for 2016, 2017 and 2018 is permanently closed.
To file a return for a prior tax year
If you need to prepare a return for 2016, 2017, or 2018 you can purchase and download desktop software to do it, then print, sign, and mail the return(s)
https://turbotax.intuit.com/personal-taxes/past-years-products/
You may also want to explore purchasing the software from various retailers such as Amazon, Costco, Best Buy, Walmart, Sam’s, etc.
Remember to prepare your state return as well—if you live in a state that has a state income tax.
When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s. Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.
Note: The desktop software you need to prepare the prior year return must be installed/downloaded to a full PC or Mac. It cannot be used on a mobile device.
If you are getting a refund, there is not a penalty for filing past the deadline. If you owe taxes, the interest/penalties will be calculated by the IRS based on how much you owe and when they receive your return and payment. The IRS will bill you for this; it will not be calculated by TurboTax.
You are required to file a tax return for 2018 if your taxable income was more than $12,000. If it was not, you don't have to file, but you might be entitled to a refund of any withholding.
It's your responsibility to keep copies of your important records. You should be able to get copies of your W-2s from your employers. You can also request a document transcript from the IRS that will contain the same information, that you may be able to use to fill out the FAFSA.