If you need a place to start thinking, check out this Introduction to Global Change online course. It's two semesters worth of material on the physical nature of global change and the human impacts involved. Try a few of the lectures. You might be amazed/shocked by what you learn.
Need more ideas? Attend a Jimmy Buffett concert! Seriously, $1 of every concert ticket sold supports Singing For Change, funding projects that improve the quality of life for people and empower individuals to effect positive change. As stated on their website:
Here's a start: What in Northwest Florida do you value? What do you want to see changed?