Your bow skills are maxed but you cant use bow? I'm not sure what you mean. It may be that, you already have the skill or you class cannot use bows.
As for certian leval to use, no. It may be that you are equiping the bow but note: you cannot fire a bow with the same button as auto attack. There will be a new button in your general list, called "Shoot" or something. This is how non-hunters will fire.
PS. What class are you? Not all classes can use bows.