Bonjorno!
Milan is a nice city to visit, I was there in summer and it was in the mid 30s seemingly all the time (including at night), which was difficult for shooting good photographs.
I did find that the city is overall quite industrial and that the 'city centre' for tourists (Duomo area) was extremely busy (especially at night?!) - which made for difficult shots or added to the feel, whichever way you want to look at it. This will probably be better for you because of the time of year, it'd be nice to get some shots on the piazza opposite the duomo and looking at the architecture on the north side (where the iconic Galleria Vittorio Emanuele II is). This does look nice lit up at night, possibly the best time to view it.
I also suggest talking a look around the Arco della Pace (the arc of peace) and the castle area (closeby), there may be some interesting shots to be had here, I didn't have much time and chose to stay in air conditioning where possible.
Navigli offers milano nightlife for coffee shop/cafe bars which have a nice atmosphere... there's also a canal running through the street (the canal is the street's namesake, it's very easy to find). Worth a look to capture atmosphere, this place looks its best in the evening.
The thing that I will say about Milan is that it does feel a bit run down - but the Italians are lovely, there's a lot of character in the city and there are hidden gems if you're willing to try hard to find them. Try the pizza on "Via Giuseppe Mazzini", Walk south from the Duomo (stay on the same side of the road) and it's a couple of hundred meters down (Much cheaper and better than on the Piazza!).
Watch out for people selling rubbish toys and remember that nothing is ever free! (Even when they swear it is!)
Have a great trip
