Nowadays too many people aren't aware of their health because of not knowing how it works. Today I'm going to assume the role of teacher and explain to you as much as possible and give the most helpful information.
1. The first nudge in the right direction is to count your daily calories. It means that you need to know how much energy you should take for your body and it is usually much less than you take now. For example, my weight is 85 kilo so I need to take 2500 calories per day. You can check it for you by the link:
2. The next thing that you should keep track of is your physical activities, and it is a myth that you need only 10000 steps per day, it's nothing. At least two times a week you should take part in any sports activities that you like. It can be a gym, swimming, running or anything else where you can lose a lot of energy by backbreaking activities. It will improve your body consistency and immunity.
3. Another tipping moment in your life should be to normalize your sleeping timetable. It could be hair-raising to wake up from 5 to 7 a.m., nevertheless it will boost your brain activity and give you a bit more pleasure hormone. Also keep in mind that you need to sleep 7-9 hours in a completely dark room at 18-20° C in ideal.
Overall you shouldn't settle for your knowledge which you take from typical places like school or your parents, they usually don't competent in these questions. You will be living with your body the whole life therefore you mustn't allow yourself not to be aware of your health.