It is appropriate to characterize the abnormal findings, described in the text, as 'Early emphysematous changes with small bleb and bulla formation'. This is like looking at a snapshot but provides no information about your lung function, and that is what counts. To get that, you will need to have complete pulmonary function tests (PFTs). Based on the information provided, it is likely that your PFTs will show mild COPD with emphysematous changes.
Calcification, presumably of the coronary arteries may or may not be of concern, depending on the extent of the calcification and whether or not you have symptoms of coronary artery disease. For example, is this degree of calcification average for a man your age or excessive? If the latter, you should seek consultation with a cardiologist.
The very good news is that, despite a 50 pack-year history of cigarette smoking, there were no findings to suggest lung cancer.
Congrats on quitting! That's the BEST thing you could do for your lungs, body & life, as well as those of your loved ones. While there is nothing to reverse any damage already caused by smoking, avoiding smoke & lung irritants will help keep your lungs as healthy as possible and should enable you to have a very good quality of life for a very long time.
Starion