Getting excited in this hobby is a good thing, just remember to ask questions, research each item first and don't always go with the recomendations of your LFS
. Take your time and don't rush and you will have an awesome tank. You don't have to break the bank either.
As Cmor said get sand and just seed it with some LS
from an established tank. A lot of LFSs will sell LS
by the pound. Get some from them to seed your tank. Along with Base rock and some LR
you will be well on your way to starting your tank.