If you're not ready to setup the tank then your first purchases should be marine salt, refractometer, heater, cheap circulation pump and a bin to keep the rock. Get some saltwater mixed up, fill the bin to above the top of the rock, put in the heater and pump and let the rock sit. If it dries out you're basically starting with dry rock which is fine. It just depends how you want to start your tank. If the rock does dry out you're going to have to cure it to get it going. This can be done in the tank but make sure you don't add any livestock until the cycle completes because you will get an ammonia spike with all the dead stuff on the rocks. Most folks cure it in a bin if the rock has dried out.