Since your question is about the bitcoin daemon and not the WordPress plugin, you might have more luck asking at channels related to the Bitcoin wallet, such as https://bitcoin.stackexchange.com or https://bitcointalk.org . Having said this, here’s a few things that come to mind:
You will probably want to install
bitcoind as a service, not just run it from the command line. Most installation guides tell you how to do this for your system. Perhaps the installation process that you performed has already done this? It could well be that bitcoin is running. Try a
bitcoin-cli getbalance and see if you get a number as a response. You can also check to see if the daemon is running with
ps ax | grep bitcoind. To see if that port is open do
netstat -a | grep 8332.
Let me know what you find.