Scotland is in the UK. So is some of Ireland, for that matter.

I would say "one's English"

I have been told it's easy for Brazilians to go to Ireland. I have met many Brazilians who have studied English in Ireland. You should look into it. 

Malta in Europe is a good place to this?

USA . English is marvelous with American accent :)

I know nothing about you. But if you're college students, it's easy to travel, because there are some programes for students. For instance: you can go to work abroad during your holidays. I've been in USA within this pragram.

If you're older and you have job already, it might be harder to leave everything behind you and go abroad. But why not, it's up to you after all.