I'm 15 and i want to become a lacto-ovo-vegetarian. Please help me.?

Okay, i dont know how to exactly get started... like i want to first cut out red meat, then chicken, and so on. So once im a lacto-ovo-vegetarian, i can become a complete vegetarian. (only eat plants). I just need some starting tips, and will i need suppliments for the minerials ill be loosing from not eating meat? Oh also, im cutting out all sweets and cokes from my diet.