Breastfeeding newborn while weening toddler

Hi🤩 my son has been exclusively breast fed since he was born, he’s going to be 2 soon! so we’ve been trying to get him off for awhile! He is fine taking his cup and everything else during the day but still wants the boob at night and whenever he’s sick, etc! We’re going to have a newborn in a month that I plan on breastfeeding as well so if anyone has any advice or tricks on what I can do to keep him from breast feeding so much and if anyone has been in the same situation, how did it go for you?