You don't need to even cut off the fronds.
Ferns are pretty maintenance-free plants. If you leave the fronds (which can be pretty in the winter), new fronds will just grow up through the previous year's growth. Old dead foliage will create a "mulch" around the plant, keeping down weeds and keeping soil moisture in, then will decompose feeding the plant. This is the natural and normal way for ferns to grow.
You do not need to fertilize.
If you are not sure whether this is, indeed, a cinnamon fern, you are welcome to send us photos of the fronds in the spring, after they unfurl. We can identify the species for you.