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 the card is converted to "Internal" storage, it will be formatted (wiped) and encoded (making the cards data only readable by that device).
1. Go to device “Settings”, then select “Storage”.
2. Select your "SD Card", then tap the “three-dot menu“ (top-right), now select “Settings” from in there.
3. Now select “Format as internal”, and then “Erase & Format”.
4. Your SD Card will now be formatted as internal storage.
5. Reboot your phone.
NOTE: If you don't reboot the phone, many things may not work correctly, so make sure you do.