Server not responding after fresh install

I have a new nonprofit license for cPanel; though, I have yet been able to access cPanel after installing. I use a GoDaddy-served VPS. Plesk, when installed, works fine. I decided I preferred cPanel from my experience using it for my shared hosting account on GoDaddy.com. I am not an IT person. I am a web developer who is delving into Node.JS coding and was not happy with the level of control given to users of the shared hosting platform for the purpose of creating Node.JS-based, server-side scripts, e.g. limitations on routing, post method handling and routes, etc. The VSP build is running on CentOS 7. After running the install script associated with my account, I get the typical installation resolution screen: cPanel install finished in 18 minutes and 9 seconds! 2018-12-19 23:05:12 1264 ( INFO): Congratulations! Your installation of cPanel & WHM 11.76 is now complete. The next step is to configure your server. 2018-12-19 23:05:12 1264 ( INFO): Before you configure your server, ensure that your firewall allows access on port 2087. 2018-12-19 23:05:12 1264 ( INFO): On RHEL, CentOS, and CloudLinux systems, execute /scripts/configure_firewall_for_cpanel to accomplish this. 2018-12-19 23:05:12 1264 ( INFO): After ensuring that your firewall allows access on port 2087, you can configure your server. It proceeds to give me the IP address and port number to access the cPanel GUI. Unfortunately, when I go to the IP address and port, the page does not load. I get an error: "Safari cannot access [ip address and port] because the server where the page is located is not responding" OR "The connection timed out" on Firefox and Chrome. When I run the script to ensure that port 2087 is not blocked by default on my VPS, /scripts/configure_firewall_for_cpanel, I get the following: iptables: Chain already exists. iptables: No chain/target/match by that name. [... 30 times or so ...] iptables: No chain/target/match by that name. iptables: Saving firewall rules to /etc/sysconfig/iptables:[ OK ] Redirecting to /bin/systemctl restart iptables.service ip6tables v1.4.21: can't initialize ip6tables table `filter': Address family not supported by protocol Perhaps ip6tables or your kernel needs to be upgraded. Could not open socket to kernel: Address family not supported by protocol [.. 30 times or so ...] Could not open socket to kernel: Address family not supported by protocol. ip6tables v1.4.21: can't initialize ip6tables table `filter': Address family not supported by protocol Perhaps ip6tables or your kernel needs to be upgraded. I am not sure whether the script fails because it runs different variants depending on distribution, but at least the first iteration "exists." I cannot get IP6 information on my VPS. GoDaddy does not appear to disclose IP6 information anymore for VPS accounts. But it shouldn't be necessary either because I am making an IP4 request. I followed the installation manual, including for customizing the configuration files. All the configuration files are standard and accurate. I checked the resolvers configuration file, and it includes two ns lookup sites plus "search localhost" or some variation. I've looked at YouTube videos on installing cPanel to see if I am missing something, and in each, they install, open the IP address and port provided at the end of the install, and it takes them to the GUI to set up the admin account. I don't have that luck. I performed a yum distribution-synchonization, ensured all my packages were current and up-to-date, etc. Everything's good. I have rebooted the server multiple times, as one complaint about a similar issue on Google was resolved after three reboots but no such luck here. What am I doing wrong?