Hey girl hey!
The first thing I'd say is to start focusing on the things about yourself you like. The mentality you have about yourself now will stay with you no matter your appearance. Next, start small and don't underestimate small consistent steps. Have two glasses of room temp lemon water every morning. Once that's part of your routine, shoot for 8-10 glasses of water per day. Once you've gotten that down, add a new fruit or veggie into your diet. I recommend greens. Experiment and cook it all kinds of ways so that you learn how to eat it. Once you've got that down, add in another fruit or veggie, and keep growing in this way. You'll naturally start to weed out the foods that you already know don't help your body.
Thank you for asking us your question! Sending you all of the good vibes on your journey!