I have a 2017 W-2 that I never filed for a tax return but I am currently doing a 2018 return should I added the 2017 to this one or wait and create another one?

You need to file the 2017 W2 separately on a 2017 return, which you can still do by following the instructions below -

https://ttlc.intuit.com/replies/3301770

Sorry you have to file each year separately.  So you need to file a 2017 return.  How much is the W2?  You might not have to file.  Are you a dependent on someone else's return like your parents?

You have to print and mail prior year returns.  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 received the return.  Don’t forget state.

If you are getting a refund, there is not a penalty for filing past the deadline.  You have 3 years to file for a refund.  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.

How to file a prior year
https://ttlc.intuit.com/questions/1900990-how-do-i-file-a-prior-year-tax-return

Or If you have a simple return You can fill out the blank forms for free.
Here are some blank forms & instructions for 2017
1040 https://www.irs.gov/pub/irs-prior/f1040--2017.pdf     
Instructions https://www.irs.gov/pub/irs-prior/i1040gi--2017.pdf

1040A https://www.irs.gov/pub/irs-prior/f1040a--2017.pdf    
Instructions https://www.irs.gov/pub/irs-prior/i1040a--2017.pdf

1040EZ https://www.irs.gov/pub/irs-prior/f1040ez--2017.pdf    
Instructions https://www.irs.gov/pub/irs-prior/i1040ez--2017.pdf

2017 Tax Tables https://www.irs.gov/pub/irs-prior/i1040tt--2017.pdf
Publication 17 Tax Guide for 2017 https://www.irs.gov/pub/irs-prior/p17--2017.pdf