Congrats on your coral purchases
I recommend testing and supplementing the following: PH, alkalinity, calcium, magnesium and nitrAtes.
Depending upon which salt mix you use (not all have the same values of the above), you may need to supplement all newly mixed salt water to reach the disired levels:
Reef Aquarium Water Parameters by Randy Holmes-Farley - Reefkeeping.com
Use this calculator to determine exactly how much supplement to use:
Reef Chemistry Calculator
Regular weekly water changes using a good saltmix should provide everything your reef needs. Only once the reef becomes heavily stocked (or lack of water changes is an issue) is when you will need to supplement your reef tank.
Continue testing weekly for the above values to keep an eye on the values.