new player here and this game is alot ..last mmo placed was dc universe online.

1.) are jobs of land and hand necessary?
2.) for a job class, do you need the required secondary class at level 15 or any other class at level 15?

3.) what is materia

4.) the 3 new job classes, do we start off with those job classes or is every job requires a level 30 and a level 15 secondary job?

thx in advance for answers .