All EEA and Swiss national students can work in the UK (during or after their studies). From 1 July 2018, Croatian nationals are no longer subject to the Worker Authorisation Scheme, and therefore can work from this date without obtaining permission. If you were someone who was required to obtain an accession worker authorisation document under the Worker Authorisation Scheme, it is important that you keep the document(s) you were issued.
If you require a Student visa to study, there are restrictions on both the number of hours you can work and on the type of work. It is a criminal offence to break these rules, so it is important that you check the restrictions on work before you start working and are clear on what you may and may not do.
Top tip: Check the UKCISA website for the latest guidance on working if you're a Student visa holder.