To everybody that will make such an internship in a non-German speaking country, I advise you to take a language course. For your CV, you had to take test about your language skills and the Mobility project says, that you should be at least on the level B1 to go abroad. I personally would say, you should be a bit higher than that, like B2 or C1. These levels are from the "Common European Framework of Reference for Languages" (CEFR). CEFR is a globally accepted framework to examine your usage of a language. A1 is a beginner and it goes up to C2, which are “experts” or people, who can speak that language as good as their native language.
(picture from: http://gostudylink.net/en/blog/cefr-levels-explained )
Currently I am not taking any language courses in Glasgow, but that is only because I already went one month to Bristol in September, to learn English. In Glasgow, you may have to get used to a very different accent, but I realised, that the course I took in Bristol, made me very
comfortable speaking English. Even though I don’t have a very big vocabulary or I may find it
sometimes difficult to understand the Glaswegian accent, I feel as comfortable speaking English with others as I am talking in my native language (Swiss-German).
Therefore, I can only advise you to take a language course yourself during your internship. There are many short-term language courses at the "University of Glasgow" and you may even get a slight staff-discount. ;)