Super confused about lucky buddies, berries and dragon island plus bonus unlucky buddy story

Okay there are seasons? Everything resets? All the berries I've collected, will they reset in a few days? How many berries do I need to complete the island? I have 1,200 right now.

😡 I upgraded to the max on one of my heroes, when to close the app, dropped my phone on my face and it hit the thing to buy the stupid skin. Istg that is the most unlucky thing that has happened to me in a long time. I almost gave up the offer.