LL.B in Law (full time) takes 3 years. For direct entry to level 2 or final year, I don't know about now but It wasn't allowed when I was doing my bachelors due to the law society requirements in this country. BUT if you have done certain modules that are taught here then maybe you'll be allowed to skip the entry level.
International students have to pay a hefty fee unfortunately, you are looking at the region of £8.000 per annum and the fee increases by £100 or so every year. Taking out a loan here is done via the Student Loan Company and once you have graduated, your repayments start the following year; only though, if you are earning more than £15,000 per annum, and then small repayments are automatically deducted from your account on a monthly basis.
You student loan from Canada will be worthless here. You'll have to clear that separately. Re citizenship, just search for Home Office in Google and read through the home office website for entry requirements.
Good Luck!
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PS** It'll be better If you either email or telephone the student services of the Uni' you wish to enrol at for further and more accurate information.