Take this week to do some reading. Either get a book from the LFS
on setting up and maintaining marine aquariums or find articles online. The LFS
is giving you bad info and you'll end up with dead fish and discouragement.
The worst thing about this hobby is that patience is rewarded. I'm a naturally impatient person, so it is HARD for me! Lol
However, the practical voice in me says test water, do PWC
's, setup a quarantine tank, don't I overstock and plan, plan, plan.
When in doubt, ask in the forum. No one will get mad at you for asking too many questions.
We all hope you have a great SW
experience. Just know that it takes time.