There are 3 drop-down lists at the top of the screen. Make your choice using these lists. When you have chosen something in each list, the table will paint some squares yellow for you, and probability will be calculated, by counting the number of painted squares and dividing by 52, the total number of cards in the pack.

Take your time, and play around with different combinations. You'll soon get the idea.
Note that the probability is the probability that a single card, drawn at random from the pack, satisfies the conditions.
Have fun while you learn!