@wwyxdo as @jjb45 and @Anonymous says. Asap get a sim, activate and register. And don't forget to choose the correct plan. Since under the promotion, switching plans later looses it. You can always unlock an old phone and pop your SIM into it to make sure it's working properly.
Also, when on the closing day of the deal you have until 11.59 PM eastern standard time to take advantage of it. That is if you care to live on the edge.
