Okay $4.20 a # is not to bad since you needed the rock anyway.
1) add the base rock to the bottom of your reef structure Now.
2) how long did the lfs say it would take before the lr comes in?
3) add a total of (2) shrimp now
4) when the Lr comes in even if it's nice and fresh, give it a light brushing to remove anything that's dead
5) add lr to tank
6) I hope you bought a test kit!!!!!!!!!!!!!!!!
7) test water for ammonia, nitrite, nitrate & PH
8) wait for am,n02 to get to "0"
9) get NO3 (nitrate) reading and post it for us
10) do the big water change 50%
11) enough for now, we'll advise you on the rest later..
TC