If you did not have any W-2 income during the year 2017, then do not enter any W-2 information into your 2017 tax return that you are currently completing.
Next year, when filing your 2018 taxes, you can add that you also then have W-2 income and can enter the income for your 2018 W-2 job. You will receive a W-2 form from your employer in early 2019 and the data should be entered exactly as reported by your employer on the W-2.
If you are not creating a return for 2017 using the TurboTax app, then you can certainly enter all of your 2018 set up information, including your W-2 employer so it is set for filing taxes in early 2019.