You need Ethernet connection. Then one created a World. Press Esc and then open to lan. If you are both connected to your Router vie the LAN cables the other.
A beacon is a block that projects a beam skyward, and can provide beneficial status effects to players in a radius around it when placed on top of a solid.
Pressing and holding use while holding a trident charges it. When released at half charge or more, the trident is thrown and deals damage to any entity it hits.