It's all so bleeding edge right now. It also depends how deep you want to go. An increasing number of languages support wasm as a compile target, which is helpful.

Bytecode Alliance do semi-regular streams on Youtube. I think reading (recent) material on WASI (0.3) and the Component Model would be a good start.

Understanding the relationship between a host and a guest is valuable. Learning what wasmtime is and how it works is also illuminating: https://docs.wasmtime.dev

Tyty