AHi, First im a novice baker, and i have no idea how to store cakes properly

I made my first barbie cake, filled with purple yam jam with cream cheese filling, covered in ganache and Decorated with fondant (fondx)

My problem is: since i just had to squeeze in between my time making this cake, i had to start my filling and ganache thursday night, leave it out, made the fondant friday night, leave it out. And since i knew that i Am busier and no time this sat. I finished most of it last night. Tom is the birthday to where its for. Im worried that it got cream cheese filling in it. And it has been sitting out since thurs night.

Considering the winter season so im pretty sure i leave the cake out in cool temp.

Jane

Without knowing the exact recipe you used as your cr ch filling it is hard to advise you.  Generally speaking something with cr ch should be UNrefrigerated for a total of 4 hours.   However, there are cr ch buttercream recipes that can be used w/o needing refrigeration.