If you aren't measuring, don't dose. Since your tank is just getting underway, there's probably not a lot of demand for anything.
In some circumstances, like large macroalgae populations and a lot of xenia, you may have to dose iodine, but there's usually plenty going in with the food.
Calcium and alkalinity have to be balanced. To know how much to dose, you first have to know what your levels are. Some tanks have low populations, and only soft corals , and water changes can be enough. With more demand, lots of softies or stony corals for example, then a supplement like kalkwasser or ESV B-Ionic will be needed.
Here's the way I look at Ca/alkalinity supplementation. I want to develop a dosing schedule that keeps them at target values (425-450 Ca and 3.5-4.5 alk) consistently, rather than large, occasional doses. One of the best ways to start is to use a two-part addiitive, like B-Ionic, and add small amounts at first. Measure every few days, and adjust the dose of each to get the levels where you want them.
You can also try simply adding kalkwasser in all the water you add to make up for evaporation. Things should balance out on their own.
This article really helped me understand how to dose for Ca and alkalinity.
http://www.advancedaquarist.com/issues/nov2002/chem.htm