Tomorrow I will marks the  my first anniversary of graduation from graduating the university。

Tomorrow marks the first anniversary of my graduation from the university.

Tomorrow marks the first anniversary of my university graduation.

Tomorrow marks my first anniversary of graduation from university

Tomorrow I will mark the first anniversary of graduation from university.

Tomorrow I will mark the first anniversary of my graduation from university.

Grammatically this is correct, but it sounds very formal. British say university, Americans say college.

So I would say:

Tomorrow it will be one year since I graduated from college. 

And if you were my daughter, I would say:

Great! Have you found a job yet?

And if you my mother's daughter, she would say:

Great! When are you going to marry that nice boy and bring us some grandchildren?

Seriously, Xiao Ni, congratulations!