Hi,
It depends a little on what exams your school prepares you for - English GCSEs or Scottish Highers.
You will need a good spread of subjects at 'O' level, and at least Chemistry, Biology and Physics or maths at A leve. all at A grades.
However, it is early days for you yet, and by the time you are old enough to go to vet school the entry requirments may have changed.
I believe that students living in Scotland may have preference for admission to Edinburgh and Glasgow - both excellent schools.
You must also start getting experience of working with animals in school holidays - farm, stable, kennels etc/
W