They are different tags. You will either get tags with your documents, if you requested paper documents. If you requested e-docs, then you will print them yourself. Either way they will have your cabin number on them, and you will put them on your luggage prior to arriving at the port. The #1 tags you can save and use for getting off of the ship first, if you so desire. Carnival has recently changed the way they do debarkation. In Feb. on our Ecstasy cruise we were give a blue #15 tag to put on our luggage for debarkation. This is what the #1 tag your friend gave is for. It will be the first group called to leave the ship when your cruise is over.
I know it is confusing the first time, but as you go it will get clearer.
I hope this helps
Enjoy your cruise