ok hopefully i can help, but i know a few other ppl that know more than i know will chime in...
since you are starting a saltwater aquarium, be prepared to put a lot of your free time into it. plus, we arent talking about a nano. we are talking about a 100 gal tank in a sense thats good, in a sense its bad(bc its your first tank). my first tank was a 35 gal, moved onto a 75, then bought a 28 gal nano so i can stare at it and fall asleep..
1. is there any way you can post some pictures of your setup, equipment(lights, sump, protein skimmer,etc) these starfish(some are a nuisance)? based on the total wattage of your lights we can determine a future livestock list including corals..
2. from experience, sometimes LFS are not to be trusted unless you have a really reputable LFS..personally, it's best if you learn how to test your water, etc. at first it's a pain, but eventually it becomes easier. practice makes perfect! do you know what kind of test kit you have? you def need to start to test your own water, take a pic, post it here and maybe we can help you distinguish your water levels.
3. Clean up crew!
4. (since this is your first tank) id go with some clowns, bangaii cardinals, just some nice peaceful fish etc..but lets figure out 1 and 2 before we go to 34,5+ baby steps! i just want to make sure you dont loose a lot of money! (it happened to me, just wanna protect the next person)
5. corals wise, id go with zoas and mushrooms, they are easy to keep..(for now)..
am I missing anything guys?