1099's and W-2's, etc. are not typically mailed until the end of January. You can also often access them electronically from the bank or other business in question.
You probably qualify for free file if you're thinking you may not need to file. It would be wise to draft a return using one of these programs, just to make sure you do not owe any tax. To set up an account for 2018 after filing season ends will likely cost money.
As long as you're sure you do not owe any tax or you are due a refund, you have 3 years to file the return and claim the refund and any credits (E-file, however, shuts down in November). If you find you owe money, you can also make an estimated or extension tax payment now (i.e. before April 15) to avoid penalties from applying when you later file.
Hope that helps!
