I quite frankly will just read the code. Go generally discourages abstractions so any code you jump into is fairly straightforward (compared to a hierarchy of abstract classes, dependency injected implementations, nested pattern matching with destructuring etc etc).
Regarding your IDE issues- I’ve found the new wave of copilot/cursor behavior to be the culprit. Sometimes I just disable it and use the agent if I want it to do something. But it’ll completely fail to suggest an auto complete for a method that absolutely exists.