For the record, keeping a large tank is easier than keeping a small one. Small tanks need more maintenance usually and the water parameters can change very quickly and endanger the fish.
If you just set up the tank, you would be good to go ahead and get your LR right now before you get the fish. LR has to cure in the tank before it is safe for fish. Curing is a process by which you give the LR time to adjust to your tank. Many things will die on the LR and will contaminate your tank. When the LR has finished this dieoff process (perfectly natural), the LR is considered cured. During curing you will have high ammonia levels in the tank. This is very bad for fish and is why you should put off getting fish for a little while.
Give your tank about a month to cycle fully and do a water change at the end before you add any fish so that you can reduce the nitrate levels down to lower than 20ppm.
Go slow with the fish. Many people start with damsels but find that they are agressive and are extremely hard to get out of the tank if you ever need to. They can bully other fish and kill each other. In my experience, green chromis are the most peaceful while yellow tail damsels are the son of satan.
What kind of filter system do you have on your tank? Do you have a skimmer? Do you use filtered water?
Like I said, when you add fish, go slow. Add maybe one at a time and give the tank a week or more to adjust. An immature tank has a hard time adjusting to the increased bioload of additional fish. If you try to add too many at a time, they will release more waste than your young filter system can handle. At that point you run the risk of killing what you just put in and the fish that were already in there. So go slow... this can't be stressed enough. You want saltwater to be enjoyable... so think of your tank as a garden. It will not grow overnight and the more you mess with it, the more you stunt its growth.
