I learn by playing. I gather tips here (like the building on top of crypts, or raising level of tracks in the swamps, but that doesn't mean I xill use them).
From time to time, I go read some pages of the wiki (for example, I was too much curious about those new chains dropped by Phantoms, or was wondering how useful would be those piles of ancient bark in my barn).

Compared to other games (ARPG, RTS, TBS, 4X), Valheim is very light on the spreadsheet level, and no manual is required. Also min-maxing or time optimization (like sequences of actions) are not required.