Well in regard to apps, that is only possible if you are running at least Android "Marshmallow". If you are running anything older than that, then you can't run most apps from a SD card.
Now when it comes to pictures, music, videos, etc., you can set your phone to save those to the SD card rather than the phone itself. If the app you are using doesn't let you, there are many more out there that will.
Now, if you are running "Marshmallow", then you can use the following info to made apps go to the card. If the manufacturer hasn't restricted this option on your device that is.
How to turn external SD card into internal storage on "Marshmallow".
NOTE: Please be sure you start with a blank SD card. It needs to be blank because when...