You will need to add salt to get your salinity up. Unfortunately the schedule you mention above will lead to bad results. Your tank needs to completely cycle before you can add your fish and/or corals. You will need a test kit to measure your nitrogen parameters: Ammonia, nitrite, and nitrate. Also, you need to go slow when setting up your tank. Adding 4 fish at once will overload your system very quickly.
Have you researched which fish you'd like to keep? Do you have enough light for the corals you want? These are some of the first steps you need to do to plan for your salt water tank.