how should i freeze a cake? frosted or better un-frosted? i'm using swiss meringue buttercream. does freezing cakes helps cake not to stale? and when pulling it out should it thawed first before covering with fondant?

I ususally wrap it with wax paper/parchment paper first and then wrap it with saran wrap. Wrap very well, multiple times if needed. It does help keep the cake fresh,(or make ahead of time). However I like making my cakes as fresh as possible so I don't usually freeze, I simply wrap and chill in the refrigerator. Freezing also helps for carving, it makes cakes a lot easier to handle. Lastly YES, thaw before covering with fondant, you can ice the cake itself that doesnt make a difference. If you put the fondant onto frozen cake, you will then have the cake sweeting while thawing, and then your risking the integrity of the fondant. It will also make your cake boards soggy and make a mess while slicing. HTH