Check your router and see if you received an IPv6 delegated prefix along with your v6 address. Most of the major national home Internet providers in the US should support it now - if your provider supports ipv6 they’re probably giving you a delegated prefix.

Usually you just enable ipv6 SLAAC + RA or “auto configuration” or something similar on the router and you’re done there.

Once that’s working your router should broadcast route advertisements, turn “auto configuration”/SLAAC + RA/etc on on a client and see if it gets an ipv6 address. You use this instead of DHCPv6 so don’t mistake the two.

Fiddle with the options after that, if a client supports a token you can give it something like “::DEAD:BEEF” to set its address to prefix::DEAD:BEEF.

Beyond that Google “ipv6 SLAAC” and read about it and then read any ipv6 documentation for your software/devices.