Hi,
I'm studying the same thing at the moment and I am struggling with this question as well.
Procedures would be related to the company you work for and there ways of doing things. For example, answering the telephone, filing systems, stationery ordering. If you write about some of your job tasks and the specific way the company likes you to do them.
Codes of practice - were you given a staff handbook when starting your job? This helped me a lot, it is pretty much their policies on health and safety, equality and diversity, data protection. If you read through them and relate it to some of your job task
I hope this helps.
Cassie