It is easy to share the connection. Purchase one Wi-Fi router, connect Reliance able that comes from POE to router WAN/Internet port, your PC to any of the 4 LAN ports. Configure internet connection type to DHCP or Static based on your plan.
If you do not want to buy router..you should have 2 network card in one system to share with other System. limitation is the System that has 2 Network card should be ON all the time.