UCPA courses generally have a level for everyone. Typical instruction levels range from beginner to expert; expert groups are made up of those that have been doing the activity for many years and practise it regularly, where the more advanced groups are fast paced, searching out the best terrain and working to perfect technique. Everyone, even experts, develop bad habits or have slight weaknesses - the instruction will help you iron these out and become even stronger.
Taking part in a course is highly recommended. It's a great way to get to know other people at the same level as you, to push your limits and develop your skills and they give you the opportunity to explore the area under the guidance of a local expert. You don't have to attend every session, if you want to take the morning off to do something alone, no worries just let your instructor know.