....just be aware that a fuse tap should be used to pull low consumption auto appliances (or, to trigger a relay), not with high-consumption devices (like offroad lamps and such). Read: be careful.
Also note one side of the fuse is protected by the fuse, the other goes straight to battery. This means that if you insert the tap the wrong way round, the device you are powering from the tap won't be protected by the fuse. Read: potential fire hazard!
As for things to do - what do you like? There are museums, a zoo, theatre district, market and ethnic areas, and late in the summer Toronto hosts an air show and the Canadian National Exebition. If you are into sports, Toronto has hockey, baseball, basketball and football depending on the season. Of course there are parks and beaches (of sorts) and attractions like the CN tower. There's always something going on. Once you have a time picked, they have a tourism website to check for activities here: Toronto
Camper lights were dim, but lit a little, and lit up fine with truck running, like normal lights.
This means the charge line from the truck is fine - no blown fuses or anything. The most likely cause is the battery - either loose terminals, or electrolyte too low, or a shorted cell. If the ability to deliver lots of current to the battery is compromised (as outlined above) then 6 hours may not be enough to recharge a pancaked battery.
Larger more complex refrigerators require 12V to operate, as mentioned in the other posts. The fact that it works with the truck running, shows the power line from the truck is fine.