You may have at most 15 missions at the same time, and you can give up any missions but the main ones. Goldenrod Nectar (a dim yellow colour, similar to the color of a jasmine nectar) might be made by planting a goldenrod flower (goldenrod seeds are unlocked at lvl. https://thetopdirectory.com/listings12501150/free-activities-to-do-on-your-own-up-coming-vacation