I wish you well on your quest. The first thing I will tell you is that earning any pilot certificate, Private, Commercial or Airline Transport Pilot is a lot of work and will take determination on your part. Set aside a place and the time to study. Then really study. I sat next to an airline recruit on a commercial flight from Boston to Dallas. I was still a student and he was a new ATP (Airline Transport Pilot). He was going to his second interview for his first airline job. From the time he sat down next to me and we exchanged hellos to the time we landed he studied a 4 inch thick pile of index cards with a mix of hand written questions on Regulations, Aircraft Systems components and general ATP knowledge subjects. The questions were on one side and the correct response was on the other. I adopted this method for preparing for the Oral portion of the check ride. It works pretty well.
You can also buy a home study course from Sporty’s, Gleim, ASA or King Schools. There are others but, these are the big players in knowledge test prep books and computer based training courses. The FAA just changed the entry level hour requirements for being hired at the Airlines. It is now back to 1,500 hours. It was 500-800 hours with 50 or so twin time. Most airline pilots worked through Private, Instrument, Commercial, Multi Engine then Certified Flight Instructor. Then when they met the hours requirements to be hired by an airline - poof- they were off to fly heavy metal. Now, with the regulated requirement of 1,500 hours they will be sticking in the CFI position longer. If you teach at active flight school you should be able to build that time in a few years.
It all starts with that first step and a commitment on your part. If you really want to make a path to the airlines I would start with a 4 year degree program at an aviation centric college. You will finish with at least a commercial pilot and have a real education. That will help you find employment no mater what you end up doing.
Best of luck.
CFI IGI AGI CP-I