The best answer is maybe... but it will depend on how your paperwork was handled.  Usually, juveniles are considered civil proceedings therefore are not 'convictions.' However, some juvenile cases do end up as a regular criminal case... which could be considered a felony conviction which would prevent you from being able to possess a firearm. To know for sure, you need to take your paperwork to a criminal defense attorney and let them review your paperwork to see which situation is applicable to you.