No, you shouldn't put 'the' in this sentence. The correct form is "Glasgow, Scotland's largest city..." This is because the genitive "Scotland's" is already there to make the noun definite, so you don't use a definite article as well. It's the same reason why we can say "the bag" or "Mary's bag", but we can't say "the Mary's bag". You can say 'the' or 'Mary's', but not both. You can say "The largest city in Scotland", though.

Hi how are you? I'm Jhon I wanna to talk by skype. I speak portuguese