If it's for your own personal use, I'd suggest Teeline Gold - The Course Book. Teeline isn't quite as efficient as Pitman or Gregg, but it's much easier to learn. It's essentially a progressive enhancement of standard handwriting and offers a useful improvement in speed even if you only partially learn the system. It's the standard method taught on British journalism courses, on the pragmatic basis that many journalists will primarily rely on digital recorders and won't get the full benefit from a more efficient but more difficult shorthand system.

https://www.amazon.com/Teeline-Gold-Coursebook-Jean-Clarkson...