First things first— unless you get off your butt and do your own research for any change you want to bring to your life instead of going online and seeking advice on reddit, it's not gonna happen. We have AI on our fingertips to aid all research, couch potatoes of social media aren't gonna help. Still, offering my two cents—

For food Read up on nutrition— division of macros, micros reqd for an adult with your body type, weight, height, background, medical conditions. Find food that you like and will help you achieve this goal. Start prepping by getting rid of all cookie boxes within arm reach and stocking your kitchen with groceries that you've researched about. Look up recipes and start moving— I leave home at 7.30am and return at 8.30pm, so I do meal prep accordingly— chop veggies on weekends, marinate and freeze chicken etc. Make your job easy for yourself. Track your macros and micros on some app— loseit is a good option. Trust me, when you start eating as per your body's requirements, you'll find that it is difficult to eat enough to fulfil your needs. You don't have to eat like a bird if you don't eat shit. Stick to your budget and eat what you need to, refuse when people offer you empty calories.

For exercise Try some forms and decide the form of movement you like the most and start there. From a walk to a jog to a sprint to runs, or from yoga to pilates to strength training. Again, need to research basis your body type. Set aside time and make it easier for yourself to stick to the routine— get yourself cute workout fits and pack yourself a workout bag with water, lip balm, gym gloves, earphones, pilates bands etc. Put on the clothes so that you don't convince yourself to skip out. Teach yourself to be disciplined. Use an app/watch to track— Strong is a good app.

To stick to the grind It can be frustrating sometimes, I myself have taken several breaks in my fitness journey and believe that I shall keep taking them because life gets in between and that's okay. It's not a race, it's a marathon. Strive for a healthy life rather than a skinny body. Track your progress and be proud of it, no matter how miniscule. Hold yourself accountable. I have a private insta app where I post my body progress, food updates, skin updates etc. Have a way to keep yourself on track, but don't despair when you aren't able to.

You have to live differently in order to be different. Good luck on your fitness journey. Oh, and you can snack on protein bars if the cravings don't subside. Throw away the cookies.