You should be able to change your settings so that you can download over Verizon's cellular network, but depending on the size of the download, that could eat through your data allowance in a short timeframe. Your better option would be to access wifi for free in public places, such as restaurants, book stores, etc. If you want wifi at home, you'd need to purchase a router and connect it to your home internet service (assuming you have home internet).
If the file is over so many MVP the iPhone will not let you download it unless you do it over a computer either using your mobile hotspot feature which is either free or $20 depending which plan you have.if you have another phone that has the mobile hotspot you can teathering your phone to it under wifi if turned on but be aware usage isent unlimited on that. It isent Verizon who is setting app limitations.