Depends on what you want to do. C++ isn't going away any time soon & it's probably the best for any serious applications. However, it's not an easy language to learn. I gather Python's quite a popular language for education, not used it myself yet though.
I started off using BASIC but that's really gone out of fashion. These days, my advice would be to get a Raspberry Pi & run through some of the programming tutorials available for that.