I got my W-2 form last year can I still use it

No, you cannot enter a 2017 form W-2 on your 2018 tax return.

If you filed a tax return for 2017 and did not report that form W-2, you'll need to amend your 2017 tax return to report it.

If you need more information, please add a comment.

I did not file last year's

Is that w2 still usefull or do I get rid of it

If you did not file last year, you may need to file a 2017 tax return now. It is up to you. If you are due a refund, the IRS will not say anything and you lose your refund if you don't file. If you owe tax, the IRS may write to you this year or next year to claim the tax due plus penalties and interest.
If you wish to file your 2017 tax return, you cannot use TurboTax online (as it is for the current year only) but have to TurboTax CD/Download that you can purchase at this link: <a rel="nofollow" target="_blank" href="https://turbotax.intuit.com/personal-taxes/past-years-products/">https://turbotax.intuit.com/personal-taxes/past-years-products/</a>