Depends what you’re looking for, if money might be an issue then probably commuting would be better. You said you wanted to be more sociable, living at accommodation isn’t the only way and doesn’t guarantee it. I know during my first year at Imperial, I had flat mates that just stayed in their rooms all the time. There’s societies and your course as well where you can socialise with a wide range of people.
Personally, I’d live out for the first year, just to see what it is like. As you can meet a lot of new people that’s in the accommodation. I’m similar to you in the sense that I’m not a party person myself, so I think this should help.