I am recently wondering what is the difference between a dual degree and a double major.
As far as I know, UofT does not offer dual degrees at the undergraduate level.
A double major is one of the recommended combinations of programs required to get your degree. You can enrol in any two majors, provided they do not specifically state any exceptions (for example, you can only take one major from the Department of Human Biology). A major usually requires 7.0 – 8.0 FCEs.
You can take a look at this website as a starting point for selecting your programs.