Are you rooted? Unless you root your phone, you cannot uninstall apps that came with the OS on your phone. You might be able to disable/turn them off though. Open the App drawer, go to the settings menu (three dots) and choose the option to Uninstall/disable apps. This will allow you to turn off preinstalled apps you don't use. Note that some apps cannot be turned off. If it allows you to uninstall them, then it's an app you installed yourself.