Start simple. You have lived an unhealthy lifestyle for quite a while, and you now want to establish a good, solid foundation for how you are going to live the rest of your life. If you try to do too much too soon you'll just get discouraged.
Quitting smoking has got to be one of the absolute best things you can do for yourself, so good job there!
Your body is like a computer - garbage in, garbage out, so the first place to start with food is inside your mind with your attitude toward it. Just because you can eat it doesn't mean that you should. Realize that choices you make today about what you eat will have life long consequences.
Start with the easy stuff - if you eat any junk food then stop it - food like hamburgers, fries, potato chips, etc. That stuff is just pure fat and salt, both of which will lead to cardiac trouble when you get older. And it'll save you money avoiding that kind of food.
Learn to read food labels. You'll be shocked at the amount of fat and sodium that's in some food.
Cut out alcohol, but an occasional glass of wine or a beer is not going to hurt you. The same goes for sugary drinks like sodas. Drink a LOT of water each day - water keeps you healthy and makes your skin look nicer.
Eat more veggies and salads. Salads are quick and easy - you don't have to go overboard here, a head of lettuce, some fat free/lite salad dressing, and some simple items to place on top of the salad will work. If you shop around you can find the ingredients for salad pretty cheap. Avoid regular salad dressing, it's full of salt and fat and calories.
Chicken is a pretty good source of protein, and it goes well in almost any kind of dish. You can even chop some up and throw it on top of your salads.
Allow yourself to have a meal of whatever you like once a week. That helps because you know that if you can just hang on and eat right you'll get to the day when you get to have what you want.
You also need to think about getting some exercise. You don't need to pay money to join a gym, you can work out for free - walking is free, and you are outside in the fresh air assuming that the weather permits. If the weather is bad then find a mall or an enclosed space to walk, or look around in your community to see if there are free community places that you can go to. You can join a gym later if you wish, but you need to get started immediately with exercise. Set a goal for the distance you'll walk and the number of times each week that you'll walk. If you want to lift weights you can probably pick up some used weights from a thrift store or a garage sale for very little money.
Just doing these simple things will make a huge difference in the way you feel each day, and it will encourage you to do even more for yourself.
And congrats on the new life!

~Eva