Hey Shoerbee! If you're only just staring my advice would be keep doing what you're doing!
try squeezing in rides here and there, and if you feel up to it, ditch the car and start commuting to work! That's how it started for me. My commute is 4.5km (a little under 2 miles I think) each way. That got my base fitness up enough to start taking... DETOURS on the way home, shopping expeditions etc... ^_^
Just get out there and have fun and you'll notice improovements in WEEKS!