Hi Greg and welcome to the forums
Best of luck with your plans to lose weight, here are a few answers to your questions:
1. I worked out your BMI (body mass index) as 34. Your BMI is used to measure the percentage of fat in your body, based on your height and weight. Let me stress that the BMI doesn't take into consideration the amount of muscle mass a person has, so some people believe that it is a little inaccurate, but I believe it's a good starting point. I used 110kgs as your weight and 1.8m for your height.
A BMI of 34 means that you are currently in the 'obese' category. (Don't worry - I was in the "morbidly obese" range when I first started - my BMI was over 40!) A BMI between 18.5 - 25 is considered healthy or normal, so this is the range that you need to aim for. A weight of 80kgs would mean your BMI would be 24.7, which would put you into the 'normal/healthy' category. Again, let me stress that this also depends on the amount of muscle you have in your body, as muscle weighs more than fat.
So in summary, you would need to get down to approximately 80kgs. 80kgs would put you at the upper end of the BMI range, so my suggestion to you would be to aim for 80kgs and then decide how you feel/look and if you want to lose any more weight. I wouldn't personally aim for anything lower than 70kgs.
2. At this stage, you would need to lose approximately 30kgs. I don't think that is a realistic target in 3 months. If you are planning on losing a lot of weight, it is best to do it slowly and aim to lose approximately 0.5 - 1kg a week. If you crash diet, you'll see quick results, but you'll end up putting on the weight again. I lost 30kgs myself, and it took me approximately a year to do so. There is no general time frame for weight loss, it really depends on how committed you are and how good you are with your diet and exercise programs.
3. This is a question that varies a lot for each person. What works for one person won't necessarily work for another person. My suggestion to you would be to eat as healthily as possible and to try and do some exercise. It sounds easy, but weightloss is really all about making consistent changes over a long period of time. Personally I like to swim and walk. If you were to power-walk for an hour each day, you would probably see some good results. Try and eliminate as much "crap" as you can from your diet and definitely avoid soft drinks - they are filled with unnecessary calories. Water is your best option, but if you're like me, the odd diet soft drink is fine too.
For your diet, it's up to you whether or not you want to follow a specific program or just do your own thing. I like to just do my own thing, and I try to eat as well as possible. I usually eat a couple of pieces of bread a day (for my carbs), a lot of vegetables, a couple of pieces of fruit, 1-2 serves of low fat dairy products, like yogurt, and a serving of meat. This changes a little each day, but that is the rough guide. I also snack on diet jelly when I want something sweet and have 1-2 small pieces of chocolate each day to help with the cravings. Basically, I don't do anything too fancy with my diet - eat healthy foods when you feel hungry and eliminate all unnecessary processed foods, like biscuits, chips, cakes, burgers, soft drinks etc. It's ok to splurge and have a little on occasion though!
4. I kind of answered that above - but definitely don't eat fast food when you feel hungry! It is full of calories and not a great deal of nutrition. If you feel hungry, have a big glass of water first and wait 5 minutes. A lot of the time we confuse thirst for hunger. If you still feel hungry after 5 minutes, prepare yourself something healthy to eat. Snack on a piece of fruit, a handful of nuts, low fat yoghurt, vegetables and low fat dip, diet jelly, air-popped popcorn (without butter) or a salad. I'm sure you can think of other healthy snacks that you enjoy too. If you search on this board, there's probably a lot of great tips/suggestions out there.
5. Yes! Weightloss is about being consistent and staying on track. I fell off the wagon and stopped watching my diet and I gained back 10-12kgs really quickly. Stay focused and keep trying. You didn't become 30kgs overweight in just a few months, so don't expect to lose the weight instantly. You'll need to work hard at this! Also, encourage your family members to help you with your weightloss plans. If you live at home, ask your parents to prepare healthy dinners for you etc, or if you have friends/family members who are also wanting to lose weight, ask them to come walking with you. It's much more fun with another person. Also consider playing sports with friends, like basketball or soccer, they are great for burning up calories.
I hope this helps you, keep us posted on how you're going. Some of us like to post over in Personal Progress, so maybe you could start a thread there and keep us updated. Shout out if you need anything