I have filed my return , but im worried i may have missed things as its my first time filing on my own. Can i pay the extra to have someone to few my submitted return

We have Assist and Review, where you can talk to a Tax Expert about your return and then let them review it before you file. You can learn more about this product here: https://turbotax.intuit.ca/personal-tax-software/live-assist-review.jsp

Yes but i have already filed ?

In that case, you can wait for you Notice Of Assessment, as it will let you know if the CRA has any issues with your return. They will often fix small errors themselves.

Yes i wasn't worried about CRA having issues with my return in that sense my return was significantly more last year and my earnings were about the same so i think i may have missed out on a better return.

But i guess what you are saying is you cant help review my return because it has been submitted.
My error and i wont venture out on my own next year with Turbo Tax.