If you're not limited, the maximum ticket you can get is 10 park days that need to be used within two weeks. You'll never do it all, but this will give you a chance to see every major attraction and most secondary attractions in the parks, with a few extra days to explore Disney Springs, the Boardwalk, and some resort areas/recreation activities. I'd go through the WDW website and make lists of every attraction that you want to do, every restaurant, every resort activity and try to figure out how you want to divide them over your staY. If you do stay for the full two weeks, maybe even look into a tour at the end of your stay.