For doing a planet square, whatever the number in the box is for that day you do the mantra that many times.
These Venus squares are extremely strong and you might not like the feeling from them. These do not just make you look better, they flood your soul with a flood of Venus energy. And it is permanent and continues to get stronger even long after you finished like months or years later. Depending on your personality and your other astrological alignments, this may affect you in different ways. Look at the effects of your natal Venus, and the alignments between your Venus and your other planets.