Alternately if you already have a Trion account you can sign up via their account management website. Dunno if being a former/current Rift subscriber will give you any preference though.
This game peaked my interest. I enjoy Planetside 2 but constant PVP base capping gameplay gets stale after awhile, some PVE in an MMOFPS will but a nice change of pace. I've played Firefall too and while I enjoyed that game, there wasn't a lot of PVE content and it seemed like the development had shifted to make it more of an esports game which isn't something I'm interested in.