When I log in and block websites, it doesn't seem to be working at all. I've also added these to the parental controls. Since this isn't 100%, is there a way of checking what websites are being visited? I've logged into my T3200M, but don't see the settings anywhere and the manual link isn't working.
In general it's not really possible to perfectly see an accurate list of websites that are visited. Clients would be able to connect to a VPN and from there visit any site they want without that being visible to the T3200m. (Or just use a cellular connection or neighbouring open Wi-Fi) It would be possible to see a potential list of visited sites through DNS logs, but this is extremely noisy. When you visit a website you might only see a single entry (say www.google.com) in the log, but many sites load parts of the site from all over the place. Some will have hundreds of DNS lookups just for a single site, and so it's very difficult to do this well. It also has some privacy implications.
My suggestion would be to configure the T3200m to use the CIRA Canadian Shield DNS servers with the family option. This won't be perfect, but it should block some obvious things you might not want children to see. Instructions are available here: https://www.cira.ca/cybersecurity-services/canadian-shield/configure Note that this might also have the effect of blocking things you would expect to be able to see anyway. Many sites have multiple uses, and so "parental controls" on the internet are never going to work very well.