In the Teen Titans Go! series, Raven's powers are simply established as part of her character. It's not explained how she got them or how they work. The show focuses more on humor and lighthearted adventures, and delving deep into Raven's origins wouldn't fit the tone.
However, here's what we know about Raven's powers from other sources:
* In the original Teen Titans series and comics, Raven is the daughter of a powerful demon, Trigon. She inherits her demonic powers from him, giving her the ability to control darkness, teleport, manipulate energy, and more. Her struggle is to control these powers and resist her demonic heritage.
* Teen Titans Go! seems to acknowledge this origin story as Raven sometimes mentions her father and her struggle to control her powers. However, the show never explicitly explains her powers in detail, and the overall tone is more lighthearted than the original series.
So, while Teen Titans Go! doesn't explain how Raven gets her powers, it seems to acknowledge the source of them from the original series and comics.