Looks like you're off to a good start. Look for any marks on that jewelry piece. Also look for any spots where any plating may be peeling off. If it is, it's not solid silver. If it IS silver, then you're off to an even better start.
But it's okay regardless. You're just getting started and you're learning your machine. Just keep digging and sooner or later the good stuff will begin to appear. Don't ever be afraid to dig targets in the "pull tab" range. That's where the gold is hiding. If you dig more "trash" you'll ultimately dig more gold.