I wouldn't worry about the "what" to get started. As the others have said, find a few things that you like to do & just start moving regularly!
When I started exercising in earnest (last April), my initial goal was to do SOMETHING purposeful (DVD, walking, biking, treadmill, etc.) 3x/week for at least 25 minutes. That felt manageable.
Well, once I started moving, I found that I was really enjoying certain activites and actually wanted to do more! So, I continued to dabble in lots of different activities but increased my frequency to 5-6x/week. I couldn't commit to longer durations because of my work/home schedule.
Eventually I wanted to put some more concrete goals into place, which shaped my workouts a little more. But for me, the main goal still is to just MOVE 4-6x/week for at least 30 minutes. I usually do 45 minute workouts with longer sessions on the weekends, but some days, I just don't have the time.
Good luck to you! There are so many different types of activities that are FUN. I hope you find something that you really look forward to.