Welcome to the aviation bug. Coming to POA is just another step on your already started journey.
This is the closest to a Hotel California experience you'll ever have. You can check out of aviation any time you want, but you will never be able to leave. Its a lifelong thing (love or affliction? YOU decide).
With that said, here's some reality that you need to be aware of.
1) The ability to fly for a living can be a very fragile thing. You can lose the ability for things immediately out of the gate or years after you get your pilot's certificate. Cruise over to the
medical subforum for some real life stories.
2) Because of 1, it is always a good idea to have a backup plan in case you can no longer continue the pilot path. You would not be the first, nor would you be the last to have that path denied to you at some point.
3) As there are some piloting options that do not require a medical BUT do require the absence of a denied medical (Sport pilot and gliders come to mind) you will do well to follow what was advised above and go to the AME for a consult first. If you have something that will stop you from the beginning in getting an FAA medical, this is the time to find out. Consider the consult a practice run where if you would have been denied, no action will be taken and you're still good and can now consider your updated options.
4) after you've perused the medical forum you'll see that there are some things that are a problem from the get-go. Alcohol issues, drug issues, ADHD / Autism / Depression diagnosis, other behavioral issues. These are things to keep in mind as while they may not be an issue now, may crop up later in life.
As to flying, the realities there haven't changed. The least expensive way is going to be your local flight school. The most expensive will be your aviation universities. However, with the aviation universities you can get loans to cover the flight time and get a degree at the same time. So, from a purely time point of view this would probably be the quickest as they frequently will have arrangements with employers after the schooling. However, it will be a lot more expensive than the local flight school where you're going to be generally paying as you go and taking longer to do it. Note that you will have diehards in both camps swearing their path was the only way to go. Just grin, nod, and continue on your way. Unless you're interested in a bit of arguing. In which case, have at it.
The rest of your questions are going to be the same as whatever research you did in the past couple of weeks, there will be very little out-dated information. The world of aviation changes slowly. The biggest changes recently is Basic Med which is really not what you're looking for, and MOSAIC is still on the drawing board (and even this is not what you're asking about)
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Good luck, stick around, and let us know how it goes.