The easiest way to do it is by going to a local flight school that is certified part 141 by the FAA. This will help you get the kind of credentials you need. Do not join a flight university since their programs are much more expensive and frankly very convoluted. It is best to get a rating at a time. Private, instrument commercial certified flight instructor, and ATP which is like he doctorate in aviation. That is the rating you need. Now, age is no issue since you're only 25 and assume you re healthy. Your education is not relevant since the majority of what the airlines need is experience in the flight deck and not ground school. By the time you have 250 hrs, you can be a commercial pilot and get hired. 5 years sure, not a problem, plenty of time. Get a student loan, and do it.
Good luck to you, its a very exiting carrier.!!!
Pilot for 10 years 49 years old.