Hmm, what level are your BTECs? You might be alright, but with the range you have it might be a little bit difficult to know for sure.
As for your personal statement, start with the first half saying why you want to study business and what parts of business you're particularly interested in.
The next quarter should be about work experiences you've done, and try to find some ways in which you can relate the experiences to your wanting to study business.
The last quarter should ideally be about extra curricular activities and things you've achieved (ie, DofE, prefect/head boy etc etc).
You can put a short conclusion at the end, but this isn't always necessary.