Earlier quoted context omitted.
Sign up for free using Google Sign In. Install the tailscale client on each of your devices. Each device will get an IP address from Tailscale. Think about that like a new LAN address. When you're away from home, you can access your home devices using the Tailscale IP addresses.
So basically wireguard, but you have to pay for it, and you have create an account through Google/Apple/Microsoft/whatever. Wireguard is not that hard to set up manually. If you've added SSH keys to your Github account, it's pretty much the same thing. Find a youtube video or something, and you're good. You might not even need to install a wireguard server yourself, as some routers have that built in (like my Ubiquit…
Tailscale does use Wireguard, but it establishes connections between each of your devices, in many cases these will be direct connections even if the devices in question are behind NAT or firewalls. Not every use-case benefits from this over a more traditional hub and spoke VPN model, but for those that do, it would be much more complicated to roll your own version of this. The built-in access controls are also something you could roll your own version of on top of Wireguard, but certainly not as easily as Tailscale makes it.
There's also a third major "feature" that is really just an amalgamation of everything Tailscale builds in and how it's intended to be used, which is that your network works and looks the same even as devices move around if you fully set up your environment to be Tailscale based. Again not everyone needs this, but it can be useful for those that do, and it's not something you get from vanilla Wireguard without additional effort.