On your 2018 federal tax return, you can claim any new eligible tuition fees for 2018, as well as any tuition that you have carried forward from previous years. On your provincial return it would depend on which province you are in, as some provinces no longer have the tuition credit.

Here is how to claim tuition fees in TurboTax: https://turbotax.community.intuit.ca/replies/2647973

If you didn’t claim your tuition from previous years on tax returns for those years, you will have to adjust your returns for those years to get the carry forward amount. Here is how you can make changes after you have filed your tax return through the CRA or through ReFILE: https://turbotax.community.intuit.ca/replies/2647992