Do I need to cook the condensed, evap milks and whipping cream before adding to cake holes or not?

No, they are both added cold.

O thanks! I was getting conflicting info while reading recipies and I was in a hurry. I'm making my 1st tres leches cake and don't have time to experiment. I hope my whip cream comes out ok. I didn't add stabilizers and never made my own whip cream before either. I'm a buttercream kinda girl! Thanks for the fast reply!

The condensed milk is very thick even at room temperature. Adding it to the cream and evaporated milk will make it a little difficult to mix together, however if you warm it up in the micro (about 30 seconds to 1 minute) it will make the job a little easier. You don't want it too warm though. All three different milk products work best when they are around room temp.