How much will it cost on the first day activating a sprint plan?

I recently bought an iPhone 6 plus and it has a sprint carrier. I want to start the $65 unlimited plan for it. I'm not a customer of sprint so I'm new. So I wanted to know how much would it cost on the first day starting the service plan?

I know the first bill will be more but I just want to know the initial cost when I go to the store tomorrow. NC.

Sprint's providing an exclusive iPhone plan for $50/month unlimited everything if you're on Easy Pay or Leasing plans. So on 24-months monthly payment option, you'll be paying $50 for the plan and $25 for the phone, $75/month total. No down payment. You'll also get $36 one-time activation fee on your first bill.