Sorry for my English, i will correct it in further
Hello guys, my name is BlueBrave and this is my first ever "complete" (not yet) guide!
I'm a player who enjoys playing any role, and who really likes the new champion.
I will update this guide further.

Kalista is a very mobile champion so she is a very strong kiter

PROS
+mobile
+easy and fast to farm with E
+good harassing potential
+very good kiting potential
+high lane presence
+can help her support and decide the engage in Tf (essential on bot lane)
+a right use of W can save you and your support from gank

-Cons
-Medium/Low range makes her vulnerable to champions like tristana/caitlyn.
-Can run out of mana quickly if you use q and e frequently.
-CC means DIE !!

With this build farm after the purchase of Ruunan's Hurricane will be very fast.
Try to don't waste mana for spam E, spam it just after the Mid Game
Keep Mana for the control of the Map with W

Why build Ruunan's Hurricane? Not only for the speed attack that combined with the kiting ability of Kalista is OP, but buy it for the passive: "basic attacks fire minor bolts at 2 nearby targets" combined to the E means a very fast minion wave cleaner and a sort of aoe dmg in teamfight

passive = the master of Kiting !!
Q = is your way to salvation
W = spam spam and spam, a complete control of the map will make you win
E = CC and bonus Dmg
R = use it to save your support or to engage tf, if your supp have a good CC u can call him for save you

Use R for let engage your Tank or your best stunner
dont stop kiting and stay behind your team, when you can slow enemyes with E