Your freezer should be set to 0°F.
I once had an argument (spirited discussion?) with someone who insisted that the freezer could be set at 32°F because that’s the temperature at which water freezes. I guess that would be fine if all you stored in your freezer was ice, but the freezing point of many things is lower than 32°F, which is why my ice pops (sugar water) were still liquid in the 32°F freezer.
Even if food freezes solid at a higher temperature, keeping your freezer at 0°F slows the food’s deterioration so much that it can keep for months or even a year (though taste might suffer).
Unlike the fridge, which requires good air circulation to maintain temperature, the freezer likes to be full. All those frozen-solid foods packed together help the freezer stay at temperature more efficiently.
To get the most out of your freezer, you’ll want to create zones for different types of things.