Welcome to 3reef!
Good points all.
That sand you have does sound good. As John said a refugium will help certainly, but not absolutely necessary. If you are motivated, it would be a good move. Just leave room for a big skimmer.
THat live sand in a bag you describe, sounds like something from
Caribsea.
I think that is just biologically active with bacteria. No creepy crawly stuff. You may be able to track down some sand like you want from local reef clubs or, like John said, your current sand will become active in time.
Thanks for joining! Good luck...
matt