Laning early game is hard for kat since she's squishy and not that good early, mainly use your Q to get gold, stay back and just collect XP wait for the enemy laner to make a mistake like misstep or miss an ability to deal dmg with ur dagger when they land, your daggers dropping are your big damage dealers using your E to deal dmg with them is good and it lowers the cooldown, your E is also what makes you more mobile and able to engage or get away.