But, seriously, if you don't already know C, I'd learn that first. It is extremely useful to have a good understanding of how real (vs. virtual) machines work, to get close to the metal, as they say. C will give you that.

I know some C, as I also wrote here I plainly forgot mentioning it in New programming language suggestions.

Then I'd learn Java.

I don't like Java. More precisely there are some aspects of it that I like, but there are more that I don't like. All in all I think I'd better start over again with C++ and then switching to Java shouldn't be so much of a shock. Except for the different conceptual model behind them to which you refer with your insightful and somewhat unexpected comment.