As per the enrolment information pages here, although the School expects you to complete campus enrolment on time, you will have the opportunity to complete campus enrolment by booking a slot via the LSE Student Hub upon arrival to campus.Further information should appear on that page in due course about late enrolment, but we would also advise visiting the Student Services Centre if you are unsure where/when to enrol when you do arrive. There is also information about steps to take when enrolling late here.
Please note that the School has a late registration deadline, beyond which you cannot register- this will also be published in the enrolment information page. If enrolling late, and you miss the School's induction events, it is also important to familiarise yourself with the course selection process. There is lots of information about this on the website here but also please feel free to contact law.llm@lse.ac.uk if you have any questions.