For input languages, go to Apple Menu -> System Preferences -> International -> Input Menu. Select the languages you wish to use, and check the "Show Input Menu in the menu bar" option. You should now be able to switch quickly between the input languages you have selected using the little flag icon in the menu bar.
Then, go into Apple Menu -> System Preferences -> "Keyboard and Mouse", and scroll down the list to "Input Menu". Here, you can set a keyboard shortcut for switching the input source.