I m playing an orc monk from Kojan, but since my guild is on Thestra I moved there early. From lvl 10 to 16 I ve been using the monk trainer at Veskals exchange. I ve heard that I should choose style at lvl 15 but havn t got any quest from the trainer. But it seems like I m learning skills from all disciplines. Is it possbile to gett skills from all the styles if I chose a path? And how should I do choose a style?

As said above head to the khal trainer.  As far as your normal skils yes some of them will say dragon or drunken etc .. but after you chose a style you will be able to use Aum to learn Special skills that are applicable only to the style you chose.  You get new ones every couple of levels just like regular spells so make sure and use the aum you get after finishing the style quest every couple levels.

after you completed your quest, you should have a new ability in your book called AUM of the Raoring DRagon, or whatever the other 2 may be for drunken or Harmonious. If it is not in your book, then go to the trainer and it may have to be trained through him. After that, you will want to meditate and chant your aum at every level or every other or something. Whne you chant your aum, you will then get blue messages stating that you have learned blah blah blah. The ability will be in your book and you then make hotkeys.

You will want to continue this process until it says in your spam area "you have nothing new to learn at this level"
Some levels you will learn one ability while others you may learn 5, some levels none. You still need to go to a normal trainer may it be in veskal's or khal or arlinora's retreat, ect to learn the basic monk abilities that all monks learn. Those are the ones you have to pay for (except level 50).

Keep in mind that to learn your mastery abilities, you must have a certain amount of jin to do so. I recommend killing a mob or 2 to get full jin, then go sit in a safe spot and meditate chanting the aum. You will have to click the meditate before every aum chant, so it can be a lil timely training.

I hope this all helped you. Welcome to the mastery of Monks! Btw, which path did you chose if you don't mind me asking?

Also be aware of a bug that messes up your chain/reactoin hotbar when you chant the Aum.  I dont know if this happens to everyone but I have to relog every time I use it to get the bar to reset.  Grats on your new skills