(warning: long)
first, you have to be a male cat.
then head to fallenclan territory (tap the arrow beside hawkfeather, the white-grey shecat, and go right. head towards the upper right arrow on the screen)
then just walk until you see yellow and pink tulips. tap on the body of pink tulips and head back to fireclan/sunclan and give the tulip to her
those are just the first steps, it's complicated ;-;