Since Seggy mentioned me, I'll point out that a lot of good advice has been handed out.
I'm surprised you've searched the internet and not found the answers you're looking for....here's how I would approach your position, as I am roughly your age and started this 10 years ago.
Too many aspiring pilots put the cart before the horse. This is a journey with a series of milestones along the way. The goal of flying for an airline is absolutely attainable and you can get there - you have to spend time and some money to start that process. Keep your eyes open as you do so, and do not target fixate; goals, desires and industries change - focus on excelling at the task at hand and suddenly you'll find yourself with a certificate in no time.
1) Check out a couple of local flight schools - their rates for aircraft rental and instruction should be comparable. Schools that have a full-motion simulator generally are indicative of a place not teetering on the edge of bankruptcy. You should also look hard into Flying Clubs - they will cost a little more up front but you save money and gain flexibility in the long run.
2) Take a discovery flight - this is usually a discounted 1-hour Discovery or Adventure flight where you get familiar with a basic training airplane and the sights and sounds of what operating a General Aviation training airplane is like. At the end, they will try and sell you on the training program they offer. This is fine; my school signs up a lot of students that way - but we're also up front with the costs. We're in an expensive area and we tell students to budget approximately $14K for a Private Pilot certificate. It takes, on average, 55-65 hours to earn the certificate despite the minimums being 35-40.
3) Did you like the flight? Hold on - you've two other things to do:
4) Are you a US citizen? If so, you're in good shape. Find your birth certificate and driver's license or passport. Not a US citizen? You need to apply for training approval with the TSA. That will cost you $130, take a couple of weeks, and you need to be fingerprinted.
5) How's your health? You need an aviation medical certificate. Seek out an Aviation Medical Examiner - local schools and pilots will have names of docs they recommend. Will cost you $100-150 or so.
You don't need the medical RIGHT AWAY, but you cannot earn your certificate without at least a 3rd class medical. Getting that out of the way and making sure you CAN hold one is a good idea, because it will keep you from wasting money to find out you cannot. If you do not have a history of drug abuse, DWI, diabetes, cardiac problems, mental illness, hyopglycemia and a few other things you should be fine.
Start there. Your first priority - if you want to do this - is understanding the costs, requirements and time commitments of the first certificate.
Try to fly as often as you can - 3 times a week is ideal. Work with instructors who will do a pre- and post-flight briefing and work from a known course syllabus.
Good luck.