How thick should the rotors be and how thick should the pads be?

I figure I might have to replace everything so I picked everything up but wouldn't mind returning some of the stuff tomorrow cuz I don't have to replace it


That meaning I am not made of money and don't wanna have to replace parts that don't need to be replaced. I assume the front rotors since they are original, definitely gotta do fluid but I haven't checked out my rear rotors and pads yet.