I want to join the national guard...but...?

having a sealed record doesnt mean anything, its still viewable by the military and those who handle DOD background checks. depending on what state job you have it may or may not be something that they dig for. some background checks date back to the day you were born, some only the last couple years. also what you were convicted of might not mean anything to your employer especially considering that it was as a juvi... however it is a big deal to the military.