Wow - this is a textbook case of how a lfs misdirects a novice. Shame on them! IMHO it is very important that you rehome the damsels. Your tank should be able to eventually display some beautiful fish, but should any of the damsels survive the high ammonia levels, they will be come highly aggressive and attack any other fish you add, and even your hands (they can draw blood). So, out with the damsels asap. Get some liverock and more base (not live), a total of around 80-90 pounds should do it, and add it to the tank. If the ammonia is at 1.0 when you add the rock, do nothing else except measure ammonia, nitrites and nitrates. Within a few weeks the ammonia levels will fall, the nitrite level will rise, and finally the nitrites will fall and the nitrates may rise. At this time your tank will be ready for the addition of fish, but only 1 at a time, and optimally, after quarantine. There are plenty of threads here about how to set up an effective and inexpensive quarantine tank. After more than 40 years of keeping marine fish I can assure you that an effective quarantine will keep more of your fish alive than will any other filter, skimmer or whatever, that you have in your system! Welcome to this site. You will find good advice here from fishkeepers who have no financial interest in selling you something, and are only interested in your success in this sometimes frustrating hobby. I say frustrating because I am personally frustrated at the terrible advice you have gotten from your lfs, but have patience and faith - we will get you straightened out.
