What grades do I have?
Depends what university you will apply for. However, because the Msc is expensive in the UK, even for the British students, the students tend to look for jobs after Bsc; and therefore some universities accept students with lower grades.

Little bit of advice: Look for the courses in details to cover your interests; For example an Msc in Computer Science at one university might involve more than theory; than the same Msc at another university.