Am I too young to have an endodontic surgery?

No. Age is rarely a factor in endodontic surgery. The real question is can it be treated in any other way. If that answer has been determined than you should proceed. If it has not been evaluated please discus the question with your local endodontist. Retreatment frequently can be used to avoid surgery.
NO. If it is necessary, then it is necessary. Make certain you are being seen by an endodontist - a specialist in endodontic therapy and surgery.
NO. How old are you ?. If you have permanent teeth no , they should be saved, , if you have deciduous teeth and 6 yr old, and yes.
No. Age is not a determining factor in most types of endodontic procedures. While there are some exceptions it is very unlikely that a dentist would recommend and provide treatement to a patient who is too young for the procedure. If you have doubts you can ask to be referred to a root canal specialist.