Hey y'all! First time trying to self-host something, I started with a local Nextcloud instance for me and my family to use. I just wanted to make sure that no outsiders can enter the instance (access it or its files) through a browser on another connection.

I don't have a DNS server so we access it through its IP address. The connection is unencrypted (I don't know if this is a problem on a local instance, but from what I've read, I need a local DNS server to encrypt it, as well as to be able to set a domain (?) name (I don't really know if it's a domain name, but I'm referring to the website name, for instance google.com). I don't think leaving it as it is (unencrypted, no domain name, only accessible through IP) will be problematic. Could other people access the server remotely with this setting? By remotely, I mean from far away. I tried out Nextcloud's own Security Scan and it returns:

Scan failed! The scan for the specified domain failed. Either no Nextcloud or ownCloud can be found there or you tried to scan too many servers.

I'm guessing this is a good thing for what I'm trying to achieve?

for reference, the tutorial I've used is this one under Linux Mint