Historically, active duty experience as a pilot has been the most reliable path to good airline employment.

But right now, for a young person in HS or college, the 12-ish years needed to apply, complete training, and serve out the incurred AD obligation will likely put you on the back side of the best airline hiring wave ever. For that reason I would suggest flying in the ANG or USAFR, while progressing your civilian career in parallel.

Re. Joe's comment about the services, if you're airline bound you want to fly fixed-wing aircraft in the military, not helos. If you go AD, USAF is the best bet for that (they have few helos and they are pretty much all-volunteer). USN has plenty of helos, and you might get assigned that involuntarily. USMC has even more helos, and Army is almost all helos. If not USAF, then USN. Navy helo pilots often have the opportunity to work as fixed wing instructors and build enough time for the airlines.

 

Theirs a delta propel program. I’ll be all over this if I was young


https://news.delta.com/delta-propels-next-generation-pilots-through-innovative-career-paths