Are eye floaters a serious problem?

No not at your age: Normal aging changes of the eye unless you see a curtain of them streaming down obscuring your vision. Then that's an EMC situation.

Depends : It really depends on the cause of the floaters. If u only have one or two and they have always been there, I wouldn't worry about it. If u have lots of them, if they r new or if they r trauma related than u need to see an eye doctor to have it checked out