there are 13 cards out of 52 that are clubs, so the probability of drawing a club out of a full deck is 1/4.
If the card is replaced and a second random draw is made, clubs will be chosen with the same probability of 1/4.
The probabilities for two independent events occuring in a row multiply, so the probability for these two cards (with replacement) to be clubs is p = 1/4* 1/4 = 1/16
If you prefer counting instead of probabilities, you can think if the same problem as follows:
how many choices are there to draw two clubs in a row: 1
how many choices are there to draw any suit followed by any suit: 4x4=16
so the final prob is 1/16