If you only have two days, then time is of the essence. While a group lesson is a damned sight better than trying to learn yourself (believe me on this, I went the latter route), the problem is that the lesson moves at the pace of the slowest student. If you get a private lesson, then it will move at whatever pace you're capable of. You're almost certain to come out of the two hours a lot farther ahead, and more ready to enjoy the remaining almost 2 days. Yeah, they're more expensive, but in your situation I'd think it's worth it.