How do I get a Job???

[Jinx]

Ok, I have searched every way I can think of and I can't find an answer.

How do I get a Job? My lancer is lvl 36, I want to move to dragoon but I have no idea what other class to level or once it is leveled, how do I change to the new job?

Oh! And what the heck are soul crystals?

Signed....confused

Searched every way you could think of... other than use google....

https://www.google.com/search?q=job+...3&q=ff+14+jobs