It sounds like the store dealt with the situation "in-house" (i.e. with a civil penalty and a trespass notice). If law enforcement was never involved, and charges were never filed, it shouldn't show up on your criminal history. That being said, be sure to comply with the trespass notice. If you were to go back into the store you could be charged with Criminal Trespass. If you were to go into the store and commit a crime, it could be charged as a felony (Burglary).
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