Currently, Python, Rust, and Java starterkits are available.
Some users have used work arounds to work in other languages. Here is one example, there are others on the forums.
There is some serious work done on C++ starter algo,
check the open pull request:
And the forum post and people involved here:
But as C1Rayn sad, this is not officially supported yet, and people using C++ are usually Terminal Veterans, with perfect understanding of the game. So starting with C++ might not be a great experience.
Even if you are not familiar with Python, Terminal is a great opportunity to learn it