I need help on making a plan to eat healthier?

I live at home and I do not buy the groceries and I'm pretty sure I'm the only one that wants to change my diet and eat healthier. I don't know if I should suggest buying healthier foods and I don't wanna make my parents spend extra money just for me its not like we're loaded or anything. I also don't know what kind of food I could take to school that is healthy. I have access to a microwave if that helps. Thanks.
I take my lunch to school everyday since the food is disgusting