Slip disc last year. Workout possible?

A year ago, I had a slipped disc. My MRI report said: "Moderate sized, posterocentral and right paracentral disc extrusion at L5-S1 level compressing the thecal sac. Right lateral recess narrowing at this level with compression of the traversing right S1 nerve root." I was on bed rest close to 6 weeks. After that I had 2 weeks of physiotherapy at home through Portea. Then, I started traveling to work and things got back to normal. I followed the 2 rules my physio told me - don't bend forward, don't lift heavy things. I really want to know if I can join a gym, or workout, or play football. I used to be an athlete, not a fitness freak though. Now I feel completely out of shape doing basic workout at home. I really want to go out there and get the freedom and flexibility to play most of the ball games. Please tell me what has to be done. Or you could also tell me what kind of exercises I can start with, so I could communicate necessarily with my gym trainer (when I join 1).