It's best to talk to your school or Business Central if you are a Business student.
If you are not sure who to talk to, just contact the Hub who will be happy to help.
I concurr wtih PhilD. If you are a Business Student, then you can either go to Business Central or look at the Business Central webpage. All business Spring/Summer courses are listed there.
If you are not a Business Student, then you could ask your school or go to the Hub.
You may be able to enrol in some courses via EOL, but others will need an EVF (Enrolment Variation Form).