As you have a PPL, it does not have to be an instructor that flys with you. If you could find a retired or not very busy professional pilot, it would be useful to take him/her along to set you little navigation exercises or other tasks to make the hour building more interesting. I flew as such with my son when he was learning many years ago and I enjoyed setting the tasks (such as how about we go to xxx for lunch) and I think he liked to have someone else along to share the experience.