Securing DigitalOcean Droplet

I really appreciated the simplicity of spinning up a SimpleHelp server using the SimpleSetup tool. This was my first introduction to DigitalOcean, and I like their pricing and control panel. The entire process between DigitalOcean and SimpleSetup was seemless and painless.

I’ve now got my SimpleHelp server running, with 2FA for the administrators enabled. While I can maneuver myself around Linux, I’m more adept in Windows. I started looking into DigitalOceans guides for securing my server (Ubuntu 18.04) but given how smoothly SimpleHelp is working, I’m a bit concerned I’ll muff something up.

If the only action I’ve taken with the droplet was to create the SimpleHelp server, is it secure? If not, what steps should I take to secure the droplet?