No, you canot fie W-2s from different years together. If you did not file a return in 2017, yo can certainly file on enow. You'll have to purchasee th desktop/CD program and file by mail. You can purchase that here:
https://turbotax.intuit.com/personal-taxes/past-years-products/
If you filed a 2017 return and failed to include these two W-2s, you would then have to amend the 2017 return. Here's information on that:
https://ttlc.intuit.com/replies/3288565
