I need help with last names for a book!!!?

I can't give you names for your characters, however they do not need to be super pretty/interesting. How often is their last name going to come up in your story? Look to the people around you, what are their last names? Borrow them. See an interesting name on the internet? Use it. Keep your eyes and ears open. But last names are not super important, they're just good for introductions, focus more on writing your story and if you need a last name add it in later when you find something you like. Hope this helps.