Even though it's tall and lanky, its still a baby, so go very gently on the fertilizer. For the first month or two, what's in the potting mix will be plenty.
It would not have grown so tall so fast if you had potted it and put it in the sun sooner, btw.
Be sure the pot you put it in has a drain hole. You don't want the roots to drown.
Keep us posted on the progress - it should dazzle you with growth in the next few months.
