Welcome back! Yeah, there isn't exactly a centralized place to find good guides on every job that I'm aware of, but I also tend to just Google them. You could also look up the Balance Discord server, as they have several people who can give great pointers on how to get the most out of any job. Barring that, you may also find some threads on the forums here under the Classes and Jobs section under each role. Hopefully between those resources you can find something that works for you.

As for FCs and such, I second Canadane's advice, and would also add looking into potential social media groups that may be out there for Zalera. I know Adamantoise here has a Facebook group and a Discord server at least, so it's certainly plausible Zalera would have similar groups. Best of luck!