ah... I don't think that is good excercise.
Calf raise though is my absolute favourite excercise of all. The great thing about calf raise is you dont actually NEED weights for it. Although any weight u can get helps, as it will reduce the length of time you have to spend doing them.
When doing calf raises make sure to go up high and down low.
And do alot of calf raises each day cuz they're awesome
Try not to chicken out too soon when it starts getting hard or it won't work so well obviously.
Give them a try, tell me if it works for you, cuz you dont have weights do u? so it might not be so easy for ya.
As for the cardio, can you try something different? something better?
going slowly up the stairs doesn't sound like much excercise.
Simply increasing speed could be good...
but you should look at other options cuz I can't imagine a SMALL set of stairs to be good cardio.
ask yourself this: how much do you sweat after cardio?