It depends on the class. Some classes, when you reach to level 30, you automatically get it in the skills tab. And other classes, you have to do a certain quest, and then you get rewarded with the first job advancement.
henseys the same place you got your first job
You go to the respective job masters.
Wizard SWORDMAN.
You go talk to the guy who gave you your first job. Then he will sent you on a quest, after you're done, there will be a trainer waiting for you.
magician
Either your first or second job is lacking skill points.
you get it from a quest during the first job, you have to do all the quests with [required] in the name to be able to get the quest
Once you have chosen a job/class from a beginner, you can not change jobs again.
gunslinger bad brawler good
you do the cygnus knights job quest the password is Francis is a genius Puppeteer!
When maple story was first born which was May 5, 2005.
You have to be atleast 13 to play maple story