Here is what you need in your pantry for most cakes:

Flour
All purpose flour, bread flour, and cake flour. You need all three types as you would use all purpose for example for basic yogurt cake, but bread flour for croissant dough or brioche and cake flour for angel food. If you must have only one type, take the all purpose flour.

Sugar
Granulated is fine. Some recipes or call for brown sugar, decorating often calls for icing sugar.

Eggs
I use brown organic eggs, but that’s because that’s what my wife buys. any would do i guess. When separating the egg white and yolks, crack the egg on a flat surface and put the white in a small bowl while keeping the yolk in the shell. Then put the yolk in a bowl where you will put all the yolks and pour the white from the small bowl to the bowl where you need the whites. The idea is that you don’t want to contaminate the whites with even a little bit of yolk (if you break the yolk) as the whites would not whip well.

Baking powder
Basic Clabber Girl baking powder.

Dry Yeast
I use Red Star Active dry yeast from Costco. Keep it in the fridge in an airtight container.