After you file

My Question is Now I can amend my Tax return for Tax Year 2017 and shall I change the filling status from Single to "married filling jointly" because now I have ITIN for my Wife?

 

Not only can you do so you MUST do so ... if you filed SINGLE in 2017 when you were really married that was a big mistake ... so amend the return to change the filing status and add any income she had as well.