As a learner driver, you have to display 'L' plates ('L' or 'D' plates in Wales) in a highly visible place on the front and back of the vehicle you're driving. And until the day you pass the practical part of your test you'll have to display these and drive with someone who has passed their test. Find out who can accompany you.
'L' plates have to conform to a legal specification, so make sure you buy them rather than making your own. Whenever the vehicle isn't driven by a learner, you should take off the plates or cover them (except on driving school vehicles).
A person who is at least 21 years of age and has held a full EC/EEA licence for a minimum of 3 years for the type of licence you are training towards.
If you have an automatic licence you are not allowed to accompany a learner driver driving a car with a manual transmission.