from 12 months it's fine to switch straight to cows milk, you don't need to do formula.
As they get older, yes, you can start to introduce sugar and salt (I think L's first sugar was in her first birthday cake!) but I wouldn't go crazy - best to stick to healthy options to avoid LO developing too much of a sweet tooth and not add salt to meals if you don't need to. There is quite a bit of salt in things like bread and cheese already. As a treat once in a while I think something sweet is fine though and it can be fun to start baking with your LO.