First, I have no experience in reno field.

But there are 2 things quite a concern in the photo.
1) the leakage seeping to the wall. It could be easy fix or expensive one. be careful and confirm with someone on this.
2) Roof leakage. I don't think you should go cheap to get this fixed because if it occurs again it could be quite troublesome and costly to fix. This should be carefully dealt with.