Check your iOS version from settings and download the jailbreak tools from the Internet remember you need a computer for a fully unethetered jailbreak.If not you can use the other method that is semi jailbreak You can also use the semijb.com website to jailbreak your device online, TaiG 2 and PP jailbreak 2 tools install the Cydia automatically after the jailbreak process. However Semi Jailbreak doesn't install the fully functional Cydia to your device after the semi JB process