Depending how motivated you are and what you want to be doing
C++ is a very powerfull and fast language and often used in games due to it being able to use things like references, pointers and generics (templates) languages such as Java doesn't have. However Java works on all platforms, making it stretch to more users if you're making a program like Skype.
C# is also a powerfull language but i don't have much knowledge of that so gg (though i have been told it has alot of features that C++ has)
However if you have close to 0 experience i advise you to start with Python due to it being easy to get in to. But don't let that fool you; programs such as youtube and instagram are coded partwise made with python