I don't think there is a yes or no answer to your question. I believe it depends on (1) the particular disposition of your juvenile case, (2) what you were convicted of, (3) the particular laws in that state, and (4) the laws of the state where new charges are contemplated.
Additionally, even if your record is going to be used against you, it will only affect your sentence. It can not be used as evidence to convict you, even if you are charged with the very same offense you were charged with as a child.
You may very well be able to read your juvenile disposition online, or you can write to the clerk of court. You may even have to visit the courthouse where the conviction took place. Some juvenile cases are sealed, and I'm not even sure if YOU can take a look, even though YOU'RE the principle.
Does sealed mean that the new jurisdiction can't get access to those records? It might, but I wouldn’t count on it.
So, the answer to your question is, it depends.......