Barb's given you wonderful advice. I think that walking is an awesome way to start a fitness program, but 2 hours might be too long....just depends on how fit you are right now. I would start off with shorter amounts of time though and work up, just like Barb mentioned. In fact....that is exactly how I got started myself!
You can definitely do this. Keep on checking in and plugging yourself into the resources, especially the new challenge. Make yourself your most important project...you are so worth it! ; )
Not eating breakfast isn't good for you. You should eat at least 5-6 times a day, with breakfast being the first meal. It doesn't have to be a lot - maybe a hard boiled egg, piece of fruit, small bowl of cereal with milk, etc. For snacks, the 100 calorie packs are good so long as you stop at one pack. When you eat a meal, try eating an apple or drinking a large glass of water about 1/2 hr before, that will help fill you up for little or no calories, so you won't be so hungry at the meal. Also try using a smaller plate (a salad plate, rather than a dinner plate) - that way you can eat a plate full, without so much food, therefore less calories. Try eating some protein and fiber with each meal because it takes longer for the body to break them down so you will feel fuller longer. Don't cut your calories too much or your body will go into "starvation mode" and hang onto any extra weight. There are numerous web sites that will assist you with calculating the # of calories you need each day just to maintain your weight, then in order to lose, you will need to create a deficit by eating less and using more calories.
2 hours seems like a long time to walk in the park, but if you are used to walking you'd be ok. If you are not used to exercising then 2 hours is much too long. You need to start out slowly - try 15 min to begin and gradually add a few minutes each day. One good thing to do is to buy a pedometer and wear it all day long. The ultimate goal is 10,000 steps/day, but you might start out with say 2500 steps and each day add an extra 500 steps until you reach the 10,000.
Good luck and visit us often for more tips, games, challenges, etc. There are lots of people who can help and it's fun.