It is, but I am starting to learn xyz might be preferable, if only to avoid the sound of the two -ing forms one after the other.


This statement is not wrong in popular English -- but in "formal" contexts you should prefer something like:

I am starting to learn xyz.

But, sometimes the former is more suitable. For example

I'm practicing dancing.

is more common (even formally), than

I am practicing to dance.

Hence, the bottom line is: use what people are accustomed to hear and read. (unless of course it's a new coinage)