Ill tell you what i did...cut out all the sugar, drink nothing but water and no fried food. Youll be amazed to how much weight you lose right off the bat from that.
If you plan on lifting, do so moderately and youll slowly see yourself define up a bit and lose some fat in the process. Weigh yourself once a week, while not focusing too much on the scale, its just numbers.
If you can walk, try doing incline between 10-15 at around 3-4 mph. That should get a good sweat, burn a ton of calories and get you conditioned for more running. Rowing machines are your friends here.
After you burn all those calories, dont think you can cheat and eat something not worthwhile. Think of everything bad and if you eat it youll gain 15 lbs right off the bat.
NO cheat meals, no garbage. This is key. I lost 15 lbs off getting rid of my bad habits.
All about discipline man, i helped my dad in a similar position like you and he went from 260-196 in 8 months. Mind you he couldnt run, bad knees and two bad shoulders so lifting was not in his favor. It came down to him cutting out all bad habits, eating healthier and just watching.
Anything you need man, we are here.