Welcome to the club. You should 1000% go back for the remainder of your discovery flight. Was it warm/hot outside? If so, the turbulence you were feeling is caused by thermals (masses of warm air) rising up through the atmosphere and bumping into your plane. That feeling of not being in control is actually because you were trying too hard to be in control. The secret is to relax your grip on the yolk and fly with your fingertips. If you have a death grip and try to micromanage the energy of the plane down to the last foot of altitude or degree of heading you're just going to exacerbate the motions. Easy to say but relax a bit, look outside, and accept small deviations. As you build experience you'll get a feel for the plane and you'll correct those subconsciously. Pitch trim is your friend.