Henry,
I recommend you take a look at our FAQ section for answers to many questions regarding the best route to a career in aviation. If you look up to the left of this forum you’ll clearly see the ATP logo and we’re all very partial to ATP because we were all in you position at one time, did our research and concluded that ATP was the right choice. If you’re not ready to make a full-time commitment to a school like ATP, Chris put together a very nice piece on choosing the right flight school: https://airlinepilot.life/t/questions-for-any-prospective-flight-school/117
Adam