There is no way anyone can say for sure if you are in a retail theft database.
But, from what you describe, I'd venture a GUESS that you have no criminal record because of the incident.
It also sounds as if you we're a minor at the time, and because of that (plus your mom and a very good hearted store manager), you're LIKELY not to be in a retail theft database.
So, why not conduct a test?
Now, if you decide to do this, it won't speak to ALL of those dastardly databases, but you'll have a general idea.
Apply for a job at a couple DIFFERENT retail stores.
If you get job offers, you'll KNOW you aren't in THAT particular database.
You can always politely decline the job offers.
Again, my guess is that your name and record are clean, so behave as if they are.
You appear to have learned your lesson, so I wish you much luck and success in life.
If you ever get the chance to do for someone what the nice man or woman did for you, please PAY IT FORWARD.