I'm pretty new to this game and there are so many classes and jobs to choose.

So I'm wondering, if I picked a class to start with and, after rolling with it for awhile, come to realize that I don't really like it much. Can I just stop playing the class at all and change to the other ones?

Yes yes, I know I can only change class after Lv.10. I'm just worry about restrictions, if there is ones, like we can't level up the other classes higher the starting one or something like that.