Gaby

You should focus on things that you can relate to the degree you're applying for in your personal statement. You also don't need certificates, they won't be checking that, there's no space in the application to submit them anyway. Doing extracurriculars just for the sake of it is not what UK universities want to see. They wan tot see that you know about the degree you're applying for, have done something around it in your spare time, and that you have the skills you need to be a successful student.