I’ll assume you mean what I mean when I say I want to be safe with my self hosting – that is, “safe” but also easily accessible enough that my friends/family don’t balk the first time they try to log in or reset their password. There are all kinds of strategies you can use to protect your data, but I’ll cover the few that I find to be reasonable.
Port Forwarding – as someone mentioned already, port forwarding raw internet traffic to a server is probably a bad idea based on the information given. Especially since it isn’t strictly necessary.
Consumer Grade Tunnel Services – I’m sure there are others, but cloudflare tunnels can be a safer option of exposing a service to the public internet.
Personal VPN (my pick) – if your number of users is small, it may be easiest to set up a private VPN. This has the added benefit of making things like PiHole available to all of your devices wherever you go. Popular options include Tailscale (easiest, but relies on trusting Tailscale) or Wireguard/OpenVPN (bare bones with excellent documentation). I think there are similar options to tailscale through NordVPN (and probably others), where it “magically” handles connecting your devices but then you face a ~5 device limit.
With Wireguard or OpenVPN you may ask: “How do I do that without opening a port? You just said that was a bad idea!” Well, the best way that I have come up with is to use a VPS (providers include Digital Ocean, Linode to name a few) where you typically get a public IP address for free (as in free beer). You still have a public port open in your virtual private network, but it’s an acceptable risk (in my mind, for my threat model) given it’s on a machine that you don’t own or care about. You can wipe that VPS machine any time you want, the cost is time.
It’s all a trade-off. You can go to much further lengths than I’ve described here to be “safer” but this is the threshold that I’ve found to be easy and Good Enough for Me™.
If I were starting over I would start with Tailscale and work up from there. There are many many good options and only you can decide which one is best for your situation!