Grand Master Schule:
Anyone wishing to become a Human Knight must have achieved at least level 20 and brought me the Sword of Ritual as proof of having passed the appropriate test.
You've accomplished neither one! Achieve at least level 20 and then speak with Sir Klaus Vasper about taking the test. You'll most likely find him around the Warrior Guild in Gludin Village. He places the utmost importance on courtesy, so be on your good behavior!