You need to report ALL of your 2017 income for the year.
Have you contacted Company A to see if they sent you a W-2? And if not, why not? Or was it lost in the mail, etc.? They can send you a copy if it was lost.
Some companies or their payroll services provide a copy of the W-2 online. You can phone them and ask if you can download a copy..
If you haven't received your W-2 from Company A by the end of February, we can tell you how to contact the IRS so the IRS can help you get it. I believe they will send a letter to your employer.
Also see this:
FAQ: Will I be able to import my W-2 before I get it in the mail?
https://ttlc.intuit.com/questions/2580775-will-i-be-able-to-import-my-w-2-before-i-get-it-in-the-mai...
