I have some tuition expenses that i never claimed for 2017 -- can i combine the amounts for 2017 and 2018 together? I literally just gave my university my SIN.

You cannot combine your tuition fees for 2017 and 2018 together.  You will need to file an adjustment request for your 2017 income tax return.  Please see the following FAQ for instructions on how to file an adjustment request.

https://turbotax.community.intuit.ca/replies/2647992