You can bake cake 2-3 days ahead of time. Wrap it in cling wrap and seal it in an airtight container so it doesn’t lose moisture.
Cake can be stored in the fridge for up to 3 days beforehand. Let it sit out for an hour to return to room temperature before serving.
You should ice the cake the day of the event. After 1-2 days it will need to be refrigerated or frozen.
Cake can last for up to 2 months in the freezer if properly stored.
After baking, wait for the cakes to cool to room temp (2-3 hours). Leave them un-iced. Seal the cakes in cling wrap, then wrap with a layer of aluminum foil. Put the whole thing in an airtight container, then in the freezer.
Move the wrapped cake from the freezer to the fridge. Leave it for at least 8 hours (overnight) to fully defrost, still in the wrapping.
https://www.bettycrocker.co.uk/how-to/how-far-in-advance-can-you-bake-a-cake