Best Storage:
Fruit bowl or fridge.
Keep citrus in your fruit bowl if you plan to use them within 1-2 weeks, otherwise pop them loose into your fridge.
Freezer?
Yes
Flash freeze slices or wedges on a tray of baking paper then pop into an airtight container in the freezer. They can also be frozen whole.
Use it up!
Use frozen citrus in drinks and cooking. Zest / grate whole fruits while still frozen.