There are no assurances.
Pilots are in great demand at regional airlines, which do not pay well or offer a stable career. The regional system prefers that pilots don't gain too much seniority so it tries to move flying around and shutdown airlines as necessary to keep pilots from achieving seniority and higher pay. Any regional pilot making much more than $50K is considered a liability, and management spends a lot of time and energy trying to figure out how to get rid of you. But they will happily allow you to start over at the bottom at another regional.
Major airlines generally offer a pay and QOL combination which is hard to beat in the 9-5 world (unless you own your own company). But it's very competitive to get those jobs.
The good news is that over the next 10-15 years the majors should be hiring at a pretty fast clip, so there's never been a better time to get into the industry. But "better" is relative...much of airline history has been horrible for pilots. So again no guarantees.
As far as regrets...
Do your research and make sure you understand what it takes yo get a major airline job, and stay focused on that until you get there. Don't even get married until after you have a major job. The opportunity should exist if you're reasonably smart, can walk and chew gum, and do the right things. Also get a PPL and fly around bit to make sure you enjoy it before committing to an expensive pro-pilot training program.
Avoid student debt to the greatest degree possible.
Do not trust flight schools for career advice...you can tell when they're lying to you because you'll notice their lips are moving. They will say anything to get you to spend money on training. Frankly the internet is the best source of info about this career, unless you know someone who is a regional pilot or a VERY JUNIOR major pilot. A senior major airline pilot came from a different era and they are usually not in tune with the industry realities of today.