What should vegetarians eat to get their nutrients?

So i'm fifteen and i want to become a vegetarian, but my dad doesn't think that i will get enough nutrients . What are some things to eat that will give me enough nutrients? I already take vitamin pills and iron pills . I don't want like a huge list of things, just some simple fruits or vegetables that give the same nutrients . I eat tofu and i know that quinoa is really good . lol sorry if there's too little detail .