Of course it will help with weight loss. Anytime you move your body, you're going to get weight loss because you are using extra effort in your day.
Cycling is a great way and depending on where you live, a very fun way to see the world around you. It doesn't burn as much calories as say running does, but cycling is less high impact on your bones.
I'm an asthmatic and to ME cycling is far easier than swimming or running. I now do it all but I started out with cycling because that was what I could handle and I lost enough weight to add and even enjoy more activities.
Good luck!