Hi raj,
I have a UK and a Canadian PPL so I can offer a little advice, but I've been out of Canada for several years and I'm not familiar with the current Vancouver flying schools.
It sounds like you want obtain a UK PPL. In that case, you will probably have to do the ground exams in the UK, unless there is a school in Vancouver that is approved by the CAA to run these exams.
If you can find a school in Vancouver that is CAA approved, then your transition back to the UK will be a lot easier, since the instructors will be familiar with both systems.
You will need a Canadian medical and a Canadian Student Pilot's licence.
Bear in mind that you will still have to study the Canadian rules, since you have to take a multiple-choice exam (PSTAR) before you can go solo. You can download the publications here:
Publications and Videos - Transport Canada
There is an exam online that is VERY similar to the real thing
:
FREE Online PSTAR Practice Exams
Having said all that, the flying experience in Vancouver will be nothing like you are able to experience in the UK. Try touch and gos at Vancouver International, fly to Vancouver Island, do a mountain checkout (in 8,000-10,000' mountains) and get some dual time in a float-plane.