I noticed on your sparkpage that you are working towards sanity, serenity, and good health.
This is probably a time to take a deep breath and relax. Nothing bad happens if you throw a little weight training in with your cardio. The only bad things that can happen starting to exercise are
1. Letting the information overwhelm you, so that you don't start.
So I agree with everyone else. Do something you like. See how it works. If you get bored, or don't like it, try something else.
Just don't try running a marathon on your first day or get into a cage match, or try lifting weights that are heavier than your car.
"There's treasure everywhere." Hobbes, in Calvin and Hobbes