Cell phone plan with Verizon how would I pay the payments credit card or in person?

[BomaniChisulo]

Going to get a Samsung S3 through Verizon came out to 120$ a month which I can afford I have just never had a plan before and I don't know how I would pay it would i just take in 120 into the Verizon store or do I have to pay by credit card? Could I pay 3 months of coverage at a time or would I just have to pay at the first of each month?
So if I went in and paid them 500$ they would keep it so that way it'll just stay on for 5 months