I have a iPhone 4 can I be on my games when I don't have internet?

Ok so I got a iPhone 4 and I play on my App games at home when I have internet but when I leave to go to school or something I loose my internet and can't go on it or else it will cost me, do App games cost me without internet too? Like Temple Run 2 or something and like Pandora?

Don't quite get what you mean, if your talking about your Internet as in it taking your credit, not Wi-Fi (home Internet) on apps that use Internet, like Facebook or stuff then yes it will use either your iPhones credit or sim data allowence. You should be able to play games on your iPhone without having Internet, like cod zombies and stuff. Are you talking about apps that require Internet to use them? Like capital radio?

Most of the games on your phone will be available to play offline, such as Temple Run 2, unless there's some kind of multiplayer element to it (online multiplayer game / MMO). Other applications such as Facebook and Pandora Radio require a constant internet connection to use them, although they will still load without the internet. Downloading apps or buying content from inside an app requires an internet connection.
If your phone connects you to 3G automatically, then there should be an option to turn it off somewhere in the Settings so that you don't accidentally use it when you don't want to.