Ok I hate when people talk and give answers about something they don't know about. Now I use many different languages including c++ and java. Now I use c++ more but this is not a biased opinion. I would have to say start with c++. Now it's not enough to say start with c++ you have to know why and I'll explain it to you.
C++ is a hybrid programming language and Java is strictly object oriented.
Now from a beginners standpoint learning classes off the bat can be really hard. Classes are such a broad subject and having to learn about them from the get go can be very confusing to the average beginner.
C++ on the other hand has a much easier learning curve, although it gets harder in the end when you're writing big robust code, it is easier to learn. Also java and c++ have similar syntax, therefore what you learn in c++ can be transfered over to java and vice versa.
With c++ you start with the bare basics: Variables. In java you start off with classes which is very broad and the downside is that they only teach you a portion about classes at the beginning to just try and let you understand it but not knowing about classes fully can be irritating.
So I can honestly rant all day about how great c++ is but tbh you already have a head start with c++ so why stop? Once you learn about classes and such with c++ you'll come to see how easy java can be.
So continue with c++ and you'll be prepared for whats in store next year. Hope this helped :)