New to Bitcoin - tips on securing my server
First of all, I'd suggest to create a separate user account for this:

adduser bitcoin

And use that account to run your bitcoind from.

You can open the port 8333 on your firewall if you want to provide a "full-node" to the network, but do not open the port 8332 (that's for RPC).

For better security though, I don't recommend using the same bitcoind instance for both wallet-storage and as a public node. If you can afford two machines, set up the wallet on one of them (this will be a "private" instance) and a "border-router" instance on another. Then make sure the private one only connects to the border-router (use connect=&lt;border_IP&gt;) configuration option. Then you can feel safe to enable port 8333 on the public border-router machine and as an optimization, you can disable the wallet on it (-disablewallet).

Once you have it all set up, you can proceed to creating an address. Run:

bitcoin-cli getaccountaddress myaccount (use any account name you like)

Here you can find a nice command reference.