"Dw i eisiau dysgu Cymraeg."
Translation:I want to learn Welsh.
There is more than one form. "I am" could be "rydw i", "rwy", "dw i", "wi" or even "yr wyf i". Welsh has different levels of formality and a major division between its southern and northern dialects. Don't worry about these variations as a learner. You can just follow whichever form you find in a course and get used to using that one. The variants can come later.