When I was 17 I graduated high school I was around 200 and at a high BF%, but it wasn't too terrible. About 6 months later I got a job at a computer repair place where I worked for a little over a year. Working there I ate terrible and never worked out at all, in that time I got up to 295 lbs which is the worst I ever weighed in my life. I felt terrible, had to sit down all the time, couldn't concentrate, the list goes on. I ended up losing the job 'cause I was never motivated or had energy to work and sat around all the time.
My father pulled me out of that one, started taking me on 3+ hour hikes with him and had me walking all the time. 20 pounds came off, then I started running, another 20 pounds, then I started getting back into weight training and ran even more, another 15 pounds. Then I changed my diet and really started being serious with what I ate, and ran even more, and lifted even more, 40 pounds came off.
I made it my goal to join the military which is what I had originally planned for after high school but never did. Finally I barely made weight at 186 lbs. In the 3 years since then I've taken my running to extreme levels, and got even more serious with my weight training.
All in all I'm down to about 7-9% bf and actual fat poundage lost was around 125 pounds. I train people now, and I feel that if I had someone training me from the beginning who knew everything I know now, it would have taken me half the time to lose the weight. But in my all around experience, it was doing the work that made me motivated to do it even more, feeling better about myself was enough motivation to do anything.
Set a goal that has a specific prize at the end of the road (like my military goal)
Find a type of aerobic exercise that you actually enjoy doing (like with my running)
Do some research, the more you read and learn about fitness the better you'll be at it and also as you learn about it, the more eager you'll be to apply what you've learned.
Reward yourself but not with food (sorry rahaas), sugary foods and pizza, soda, crap like that are things you need to stop looking at as good for any reason. If you use them as a reward you're placing them in a special positive light when you should be teaching your brain to dislike them. The longer you abstain from addictive things like high glycemic carbs, and sugar, the easier it is to keep abstaining, and eventually you'll never crave them.
Write down your goals, and write down your progress every single day. Having to sit down and write it out keeps you focused on it and you'll have a much easier time keeping sight of your goals and what you need to do to get there.
There's some tips for getting started. Good luck!
