Stop drinking sugar. This is absolutely the easiest way to atleast prevent gaining weight. I do carbonated mineral water but you can do whatever that doesn't have kcal.

Start yapping about it. It can be someone IRL that listens to you, like a GF, or it can be AI, doesn't matter. Having your own little cheerleader will make it much more likely for you to stick to your routine. AI has the added benefit of being your personal trainer. It's not perfect but it has good insight and it can help estimate your kcal burn if you exercise.

Read food labels. You don't need to go in depth and read all the substances or whatever just check the kcal on everything briefly. I used to love mayo but dropped it immediately once I started doing this. Some foods can be deceptively fattening.

Exercise is not strictly neccessary but it can speed up progress significantly. And having momentum is important, because it's a good motivator to keep going. You can do strength or cardio, doesn't matter that much. Strength will make you lose more kcal by just existing but less while actually exercising. It's more of a long term investment. Cardio is a good way to burn kcal on the spot. Honestly it doesn't really matter which one you will pick they are about the same for the time investment. IMO pick strength if your goal is to pick up girls, pick cardio if you use public transport. If you decide to stop exercising at some point your cardio gains will likely last a bit longer than your strength ones. But really its about your preference and utility.

Calorie counting also isn't neccessary but helps a lot. You can weigh your food then punch it into AI or just math it out with the labels, you can find a lot of info online about what your kcal goal should be but honestly if youre close to 1500 daily you will lose weight for sure.

Don't neccessarily eat just because you're hungry. Remember that being hungry is actually a normal feeling that normal people are supposed to feel. It's not weird or fucked up to be hungry. Besides this hunger can also be a response to you having strong feelings about something or a confusion regarding thirst. Guaranteed if you start drinking a shitton of water daily you will be less hungry too. I used to go to the fride or pantry when hungry, then I'd stare at the food and just ask myself if I really need this. Often if you decide to just drink water instead of snacking right away you'll find you don't actually need the food. Accepting being hungry becomes second nature after you do it for a bit. Not saying you should be starving yourself just that stuffing yourself immediately when you're hungry is a really bad habit. You should really be drinking on the side (NON SUGAR) most of the time if possible. If you really must eat something that isn't a main meal it should be fruit. Apples are great for this, or stuff like watermelon but that can actually be really expensive depending on where you live. Generally snacks should be water and fiber.

I did all of the above and went from 95kg to 69kg from January to August. I decided to slow down after cuz I'm actually below what my target was when I started. I went particularly hard on the cardio and water drinking and it really makes a difference. I allowed myself to snack on fruit after cardio sessions too, though some people swear by protein but my goal was really just to lose weight first and foremost. It's also important that you keep weighing yourself, I do every morning, which is probably the best time because you will be the most dehydrated so you'll get a more consistent weight measure. A lot of it is just momentum, once you start losing weight it should motivate you to keep going. The start is the hardest for sure but you also lose the most weight then so the payoff is more obvious.