Can i get an iphone without a data plan? How do i get the new sim card?

So i just bought an iphone 4 from someone at a good price. I know that my old sim card is too wide to fit into the iPhone 4 so what should i do? Do i need to buy it or can i get a free one from my account? Also, I don't have a data plan right now but do i need one? Can i get out of having a data plan? If so, how? What should i do?

I think you should make the sim card narrower by a technician. I had also similar problem and i went to operator and make sim smaller by rubbing by expert. If you have the problem them you can go operator services.