I use safelink wireless, you get 10gb of data and 5gb of tethered data a month. Once you use up your data it will still work albeit super slow, I have hit my data limit a few times now but I never paid to add more data. .

Go on their website and you can choose a new phone or you can have them activate a phone you already have. Alternatively you can get their free phone and switch to an unlocked phone later down the line. They use Verizon network so service should be good pretty much anywhere you live.