I just got started with KSP about a week ago, so I'm still learning the basics. I am trying to rendezvous two vessels in orbit. I've practiced adding maneuver nodes in the training simulations, but for some reason I don't understand, I cannot add maneuver nodes in orbit in career mode. Without the nodes I can't plan any burns. My tracking station is fully upgraded and I've set the other vessel as a target. I keep left clicking on my orbit, but nothing comes up. Also, on the left side of the navball, I should have the normal and radial navigation modes along with the target button, but the only modes there are SAS and pro and retrograde.
So why can I not add maneuver nodes and why do I not have all my navigation buttons?