As that phone is probably running "Lollipop" and not "Marshmallow" you would not be able to set the SD card as "Internal" storage rather than the standard "External" storage. Due to that, you would not be able to move most apps over to the card, as they require the use of "Internal" storage.
That said, you can move photos, music, videos, etc., over to the card, which would free up a lot of space on the phone. You can also set many apps to save the info they create/use (i.e. pictures taken, etc.,) to the card, that way you don't have to move them over.
Now if you can find a way to upgrade that phone to "Marshmallow", which 'may' not be possible, but it couldn't hurt to look into it, then you again 'may' be able to set the SD card to "Internal" storage. However, before doing so, the SD card would have to be blank. Why? Because when it is formatted and encoded to work as "Internal" storage, it erases everything off the SD card.