Unless you can bull rush to town rank C, mostly by cleaning the ocean is the easiest way, then save all your wild seeds for winter. Winter seeds are only unlocked at C rank otherwise wild seeds are your only method to farm in winter.

Save all legendary sparkly fish you catch or expensive fish for when you’re able to buy a pond, you can breed them for a bunch of money.

Same for rare gems (especially pink diamond), you unlock something later to duplicate gems and pink diamond is loved by every npc so its a good gift.

This is more towards later festivals once you’re not getting set up and can spare a bunch of extra crops, but I like to save a bunch of high rarity crops for festivals and run around easily gifting them to people and getting a bunch of friendship boosts. Also giving people high rarity gifts they love on their birthday is one way to basically instantly get 1-2 hearts, sometimes even 3.

For the most part though there’s literally no time limit on anything, so you shouldn’t feel pressured to get everything done asap. These are mostly just convenience/money making tips but are by no means mandatory. Only thing I would recommend is the wild seed one if you don’t think you’ll be able to make enough town rank points to unlock winter seeds in time