Getting a healthy lifestyle is a permanent endeavour that involves planning and knowledge, but mostly common sense. Yet, it's worth looking at the subject and sorting things out.
I've noticed that sleeping is very important yet we often fail to get full sleep, especially when we have early class or work. The key is to sleep early enough. Yet, we always try to squeeze out a few minutes to do something before sleeping, as if it would improve the overall result of the day. The difficulty to get a good night's sleep depends on a few factors, but most of the time, the difficulty is close to zero. Zero difficulty, great benefit.
A good nutrition means eating healthy food in a reasonable quantity, and not skipping meals. It's a difficult task because it requires consistency. Eating at restaurants is tempting but expensive. Making your own food is cheaper but takes more time. You have to eat vegetables, proteins, some carbs, and some lipids. Measuring food intake is annoying, yet it's the only way to have a solid control over the bodyweight. Ideally, you need a kitchen scale, or have visual clues that tell you the right quantity.
Being fit has many benefits. You look better and healthier and it raises your self-confidence. It also signals good virtues: it means you are committed to improve your lifestyle, and that you don't neglect yourself. A strong body-shape can make your peers feel safer when they are around you since you have much more raw strength than unfit people.
Being fit is one aspect of your life that you can improve and since it's time-gated, you cannot get the shape you want in one day. That's a field where anticipation and preparation are the only way to get the result you want later on. As it takes a few hours a week, It has to become a habit and if possible, an enjoyable moment. Good nutrition and protein-heavy meals are key to benefit the most out of your training sessions.