Freezer burn happens to the food when the food in the freezer has exposure to air.
To keep frozen food from getting freezer burn you need to keep the air out of the food in the freezer.
To prevent food from getting freezer burn you should wrap the food in the freezer in a double layer of plastic wrap, wax paper, or aluminum foil.
Then place the wrapped food in a freezer bag or airtight container to keep the air away from the food.
As long as you keep the food sealed off from the air and the air cannot get to the food then your food will not suffer from freezer burn.
Once the food is allowed to be exposed to air then the food can suffer freezer burn but when you don't allow any air to access the frozen food then the food will not have freezer burn.
Freezer burn is not unsafe for the food and does not make the food unsafe to eat.
However freezer burned food is less appetizing and may be unappealing to eat.
Still you can safely eat food that is freezer burned.