Or get a cheap Wi-Fi access point or router (with low range), plug it into the Sonic router, give it an SSID of tingtingcj1-guest, and give it a different password. That way, if it's necessary to change the password, only the guests and freeloaders are affected, not the entire household.
This is assuming that the current router doesn't have a guest network that's currently disabled.
This is assuming that the current router doesn't have a guest network that's currently disabled.