You are at an OpenWrt CLI which means you're almost done. If you can't load a web gui you can follow the process for upgrading from the CLI.
One thing to note is that under OpenWrt the port labeled eth0 is the WAN port and the other four are LAN, so you want to plug your PC into port eth1.
Do not plug any non-PoE device into port eth4 until you have turned off the PoE output. Hardware damage is likely to result.