A casual attire is perfectly fine for the rehearsal. Some of us will change into traditional Indian outfits in yellow for Haldi ceremony.
What kind of traditional Indian outfits to wear for Day 2?
For the ladies it can be anything ranging from Sarees, Lehengas, Punjabi suit, Indo-western outfits, etc. Amazon has some. A few other websites - https://www.lashkaraa.com/
https://www.andaazfashion.com/
https://www.houseofindya.com/
Men can wear anything formal.
What else can we do in the area?
There are a few farm stands in the town that you can visit - Lull farm, Brookdale, Kimball's. Silver lake state park, Fulchino's vineyard, etc.