Hi, and congratulations!
I went to wedding in Sorrento in 2017, and the ceremony was actually held at the Villa Fondi!
The wedding was in September, and it was beautiful! The ceremony was held outside overlooking the sea. It was a little hard to hear because of the sea noise, but it was still a stunning setting! They had a man in a cart turn up afterwards and hand out glasses of limoncello, then we all got on a bus and headed to the reception at a place called Castore.
Castore was up in the mountains, with a view over the bay and of Mount Vesuvius. It was such a lovely day and evening - the food was awesome, and the venue was just gorgeous. I'd say the reception venue was nicer than Villa Fondi, but it was quite nice to see a couple of different places. I'd recommend putting on transport for your guests between the venues though.
My fiance and I made a trip out of it - we visited Naples before the wedding and Rome after. There were lots of hotels and AirBnB's for guest to stay in as well, and getting around was pretty easy. I would highly recommend! Sorrento had an awesome night market on one of the days that we were there too.
Hope this helps! X
Edit to add - with regards to things looking rundown, do you meant the buildings? It can come across that way I guess, but I think that adds to the charm personally :)