Missions are tasks for you to complete. When complete, you are rewarded with and . Your actions will not count towards completing a mission until you click on that mission in the "Goals" tab. So if you see you have new missions, open those before you start doing things around your village!
Once you unlock Dino World, the characters will start giving you missions there as well. Buck also appears and will start giving you missions at that time.
Sometimes missions require you to buy items even if you already have them in your village. If the description uses the word "buy," items you already have will not count towards the mission. If it tells you to "have" or "get" a certain number of items, ones already placed in your village will be counted towards completing the mission.
Note: although gameloft now makes the coin reward match the level of the mission, that wasn't always the case. That's why many lower-level missions have an unknown level - those missions have been added to the tables in the general order they were received or based on a best guess. Level numbers in parantheses show the minimum level a mission could be.
Snow pile missions can typically be skipped, where the price to skip (in Acorns) is usually that of the number of snow piles, to a cap of 50
For the most part, you must fulfill the requirements of each mission in the world it is given in. For example, if Ice World Granny gives you a mission to collect from 1,000 animals, collecting from Dino World animals will not go towards completing the mission.