For those who are in Security Forces

I just recently started the enlistment process and am wanting some insight on this career field. Honestly, I've heard the best of both worlds in Security forces(whether you hate it or love it) but nonetheless id like some input. I understand that you start from the bottom (Gateguard) and work your way up but are their truly more opportunities after serving for so long? Eventually im looking to be a pararesueman but i dont have the confidence or strength to even go for it. In short, I would love some input from you guys in SF whether you like or hate it and what are the pros cons sorta thing. Thanks!