Isn't this the reason why they specifically targeted Venezuela, to get their oil?
Venezuela and Iran are strategic targets to control China's supply of crude oil. That's pretty much it.
USA can produce all the oil/energy it needs for itself. Everything else is about controlling the energy supply to adversaries.
No, the two interventions are unrelated. Every indication is that they thought Iran would be a quick war with minimal impact on oil markets. Even if they did think the Strait of Hormuz would be closed for a long time, controlling Venezuela's oil does not help — it takes much longer than two months for Venezuela to meaningfully increase oil production. (And oil is ~fungible, so it doesn't really matter if the US is involved with production and sale. All that matters is that it's produced and sold by anyone.)