I want to make dual items such as shield&sword so I try them first to understand, but instead get results like this where do I miss? is there a tutorial for dual items like shield&sword?
The demo scene contains a sword and shield that can be "dual wielded", as well as dual pistols - maybe take a look at those.
Though it looks like you may need to simply adjust the positioning of the shield in first person. This video contains a demonstration of that (from around 9 minutes onwards):
Based on the screenshot it doesn't look like your shield visible item is parented to the correct object. The setup for dual wielding is similar to a single item setup so I would first try to get it working with just the single item and then you can later adjust the item set to have dual wielding.
Your shield looks parented correctly based on the hierarchy. If you compare your character to do the demo scene character do you notice any differences?
At runtime why does the sword stay static when the hand moves? Does it change local positions?