I am in a bra 24/7, unless n shower. It has helped so much with the soreness. With my last baby (now 7) my Dr told me to stimulate nipples the last few weeks to help prepare nipples for breastfeeding. It did help some
Your breast will be sore for a while due to them trying to get bigger and the changes they go threw to prepare for breastfeeding. When they hurt really bad a hot shower makes mine feel better.
Bought seamless comfort bras just to sleep in--cheap at Marshalls & Walmart. They slip over the head. Extra support has helped. I wear maternity/nursing bra during the day. While BF I used lanolin last time and slept in a maternity/nursing bra at night but I've also heard people like those nursing tanks. Not enough support for me but might work for you.