Hello,
I am a student rep for UAL and I can help out with your worries about commuting.
As someone who does commute to uni as I don't live in accommodation, it has been a great experience for me so far. As someone who has grown up in London, I understand that it can be quite overwhelming sometimes. However, that might be because of the endless opportunities available for young students like yourself studying a creative art degree.
I know many people who have started commuting to London for the first time for uni and have had great experiences. So if you do feel overwhelmed, you won't be alone and will have a great support system between your peers and lecturers.
UAL, does offer an art foundation and I hope this has calmed your nerves a little to consider this course. I wish you the best with your application.