Other folks will have better answers, but you can read
to get some basic info.
It might help to describe a little more the kinds of things that you are
interested in -- you might get better guidance.
For assembly-like stuff, I seem to recall that Evan (Phoenix) and
Johan (Brandhorst-Satzkorn)'s work on the next
Go-to-WebAssembly (WASM) compiler iteration might
be a bit stalled -- though my information
is almost certainly out of date. You might talk to them about
where they are at with it. See
and
and the #webassembly and #contributing channels on the Gopher's Slack.