I've got absolutely no idea how to get a bucket or a bucket of milk. I tried the Bag, it doesn't respond. Interacting brings up text. There is no bucket in the crafting stations. I've tried smelting iron ingots in the furnace. The cow does not respond to interacting with an Iron Helmet, Crown, or Death Crown.
I never learned to use a Crate. It does fix inventory problems I guess but with how slow the tools are, especially flint ones, I wouldn't bother making it again.
The boss spawnkilling isn't really a big deal, it's pretty trivial after a while. I just get used to dying since it's unavoidable.
The game has a few inconveniences here and there where nothing tells you what to do, so for example: I was lost on crafting a Death Crown (you need a recently-introduced Death Crown Scroll), farming (wheat seeds can be planted but last I checked they don't work when away from water, and confusing behaviors of the Oven & Furnace.