This is an impressive start, especially for a beginner! I don't work in oils so I can't comment on approach or technique. I can only say that this is an ambitious attempt - a very busy, intricate scene with all these rooftops, and you are doing very well. I love this composition!
I appreciate you showing your underpainting - good job. For someone who has only been at this a month, an impressive effort.
Now let's let some actual oil painters weigh in here!