Dual hand crossbows does not work in 5e, nor does hand crossbow and shield.
In 5e? Yes it does. You cannot do this in BG3 at the moment, but it's absolutely acceptable in normal 5e rules.
*Edit; though, I'll allow that you do, technically need the crossbow expert feat to dual wield hand crossbows and actually use a bonus action to fire the second. Without that, you need extra attack to fire both in one round ^.^
Can you? Hand Crossbows have the "Ammunition" property, which means you need a free hand to load them. You get one free-object interaction per turn, so:
Turn 1: Both crossbows are already loaded, so you can fire both. As a free object-interaction you stow one of them.
Turn 2: You fire your equipped hand crossbow (loading it with your free hand), then free-item-interaction draw the second. However, it is unloaded and you don't have a free hand to load it, so you can't fire it.
Similar with shield, but (de)equipping a shield is a full Action, so it works even less well.
