The verb forms "would do" and "would have done" (would + infinitive present or infinitive perfect) are a bit neglected because they are not considered a tense, but a mood for unreality).
"I would go" refers to present/future time and you would do this only if a
certain condition is fulfilled.
I would have gone is the same unreal statement referring to past time.
For practical reasons I call this tense/mood Conditional 1 (C1) and Conditional 2 (C2). En.wikipedia uses the terms present conditional and conditional perfect. https://en.m.wikipedia.org/wiki/Conditional_perfect