You've made a really good first step by coming here! The support here is outstanding. I wish you luck!
(And it doesn't have to cost anything to lose weight! Walking or running is free and you have to buy food either way, right?

I actually find that buying more fresh/whole foods and fewer packaged fatty/sugary foods saves me a good bit of money.)
As a start, I would recommend that you just start documenting everything you eat, and I mean EVERYTHING! From a piece of gum to a soda to full meals. I use
www.fitday.com for this, which is also free! I try to get in the habit of documenting everything first before I try to make changes, then I will know exactly where my problems are and therefore where I need to cut back.