You can use Bifrost to log in to most Thor systems. For access to most systems, like the Thor website, you need to be a (former active) member or benefactor.

First year students will be able to enroll as Thor member when they pick up their books, or when they visit the Boardroom (Flux 6.184) once the academic year has started.

Just creating a Bifrost account does not enroll you as member of Thor.