Should I start worrying about Diabetes yet?

Hello, I'd like to start by saying I'm an 18 year old male & I am physically fit. Every time I get weighed at my doctors office, I'm usually around 169-176 pounds & my height is just about 6ft. My blood pressure has always been excellent, and I like to live an active life. I try my best to walk everyday, but if it's not everyday, it's every 2-3 days. I walk for well over 30 minutes & I'm not the type who just sits around all day watching TV. My only concern has to do with Diabetes because I am just worried that one day I will eventually develop it. My dad was recently diagnosed about 2 summers ago, but he does not need Insulin shots. I know my grandpa had it & one of my grandma's did as well, along with other relatives, Uncles/Aunts. I know it's hereditary & I'm just concerned that one day, I will get it. What can I do now to help stay healthy & not worry about it so much? Thanks in advance!