The newest portion of the GO network is a service operating between Union Station and Pearson airport, which started last year.
There are also GO Bus routes that operate further afield.
at Union there's a rather unusual streetcar stop on the outside of the underground turning loop.
UP Express is somewhat unusual in Greater Toronto (and much of North America) as it's operated by a small fleet of DMU railcars. The units were built by Nippon Sharyo. There aren't many DMUs in service in North America because of the much stricter crash worthiness regulations, which always favour a locomotive hauling carriages.
If you can manage a day trip to Ottawa, you'll see more familiar Bombardier Talent DMUs operating the O-train network there, which is classified as light-rail.
These days an App is useful too although beware of data roaming charges which for UK phones in North America can be large.